SSC CGL Tier 1 2011 General Intelligence & Reasoning Questions with Solutions

Explanation

The given number series follows a recursive pattern where each subsequent term is obtained by multiplying the previous term by 3 and then adding 6. This can be expressed by the formula xₙ₊₁ = 3xₙ + 6. Applying this to the sequence:

21 = (5 × 3) + 6 69 = (21 × 3) + 6 213 = (69 × 3) + 6 645 = (213 × 3) + 6

Following the same logic to find the missing term: 645 × 3 + 6 = 1935 + 6 = 1941

Alternatively, the differences between consecutive terms follow a geometric progression with a common ratio of 3. The differences are 16 (21 - 5), 48 (69 - 21), 144 (213 - 69), and 432 (645 - 213). The next difference in the series is 432 × 3 = 1296. Adding this difference to the last known term results in 645 + 1296 = 1941.

Explanation

The relationship in the first pair is determined by dividing the first number by 2 and then adding 2 to the resulting quotient. In the first ratio, applying this rule gives (6 ÷ 2) + 2 = 3 + 2 = 5. Following the same mathematical logic for the second ratio, the first number 8 is divided by 2 and then 2 is added to the result, which gives (8 ÷ 2) + 2 = 4 + 2 = 6. An alternative pattern involves factoring the numbers where 6 = 2 × 3 and 2 + 3 = 5; similarly, 8 = 2 × 4 and 2 + 4 = 6.

Explanation

The total number of objects in a linear arrangement is calculated using the formula T = (L + R) - 1, where L is the position from the left end and R is the position from the right end. In this case, the tree is positioned 7th from the left and 14th from the right. Plugging these values into the formula gives T = (7 + 14) - 1. This results in 21 - 1, which equals 20. The subtraction of 1 is required because the specific tree is counted twice—once while counting from the left and once while counting from the right.

Explanation

The age of Shan is 55 years. Sathian is 5 years junior to Shan, so Sathian's age is 55 - 5 = 50 years. Since Sathian is 6 years senior to Balan, Balan is 6 years younger than Sathian, making Balan's age 50 - 6 = 44 years. Devan is the youngest brother and is 7 years junior to Balan, so Devan's age is 44 - 7 = 37 years. The age difference between Shan and Devan is calculated as 55 - 37 = 18 years.

Explanation

To determine the relationship, the description provided by Vinod can be broken down step by step. Vinod's father's wife is Vinod's mother. The only brother of Vinod's mother is his maternal uncle. The son of a maternal uncle is a first cousin. Since Vishal is the son of Vinod's maternal uncle, Vinod and Vishal are cousins to each other.

Explanation

Total number of families = 80. Number of families owning a car = 20% of 80 = 0.20 × 80 = 16. The remaining families = 80 - 16 = 64. Number of families owning a motorcycle = 50% of the remaining families = 0.50 × 64 = 32. The number of families who do not own any vehicle is found by subtracting the motorcycle owners from the remaining group, since the car owners were already removed. Families with no vehicle = 64 - 32 = 32.

Explanation

The day of the week for a specific date repeats when the sum of odd days accumulated since that date reaches a multiple of 7. An ordinary year consists of 365 days, which equals 52 weeks and 1 odd day (365 7 = 1). A leap year consists of 366 days, which equals 52 weeks and 2 odd days (366 7 = 2). Starting from 5th January 1965, we calculate the odd days for each subsequent year to determine when the cycle completes.

From 5th January 1965 to 5th January 1966, there is 1 odd day because 1965 is an ordinary year. From 1966 to 1967, there is 1 odd day. From 1967 to 1968, there is 1 odd day. The interval from 5th January 1968 to 5th January 1969 includes 29th February 1968, so it contributes 2 odd days as 1968 is a leap year. From 1969 to 1970, there is 1 odd day, and from 1970 to 1971, there is 1 odd day. Summing these values gives 1 + 1 + 1 + 2 + 1 + 1 = 7 odd days. Since 7 odd days result in the same day of the week, the next time 5th January falls on a Tuesday is in the year 1971. Alternatively, any year that is one year after a leap year (like 1965 following 1964) repeats its calendar after 6 years, which confirms 1971 as the result.

Explanation

The relative positions of the five girls can be determined by analyzing the given conditions. From the first condition, P is to the right of Q (Q-P). The second condition states that N is to the left of Q but to the right of M, which establishes the sequence M-N-Q. Combining these two sets, we get the order M-N-Q-P. Finally, the third condition states that P is to the left of O, meaning O must be to the right of P (M-N-Q-P-O). Arranging them in a row from left to right, the sequence is M, N, Q, P, and O. In this arrangement, O occupies the position at the extreme right.

Explanation

The relative ages can be determined by ordering the individuals from eldest to youngest based on the given statements. From the first two conditions, Sita is elder than Lavanya and Lavanya is elder than Swapna, establishing the sequence Sita > Lavanya > Swapna. The fourth statement adds that Swapna is elder than Hari, extending the chain to Sita > Lavanya > Swapna > Hari. Finally, the third statement specifies that Suvarna is younger than both Hari and Swapna. Since Suvarna is younger than Hari, who is already the youngest in the previous sequence, Suvarna must be the youngest of all. The complete descending order of age is Sita > Lavanya > Swapna > Hari > Suvarna.

Explanation

The angle between the hour hand and the minute hand of a clock is determined by the formula θ = |30H - ¹¹⁄₂M|, where H represents the hour and M represents the minutes past that hour. To find the time between 9 p.m. and 10 p.m. when the hands point in opposite directions, the angle θ must be 180°. Substituting H = 9 and θ = 180° into the formula, we get 180 = |30(9) - ¹¹⁄₂M|. This simplifies to 180 = |270 - ¹¹⁄₂M|. Since we are looking for the first instance after 9:00, we solve the linear equation 270 - ¹¹⁄₂M = 180. Subtracting 270 from both sides gives -¹¹⁄₂M = -90. Multiplying both sides by -2 results in 11M = 180, which gives M = ¹⁸⁰⁄₁₁. Thus, the hands are in opposite directions at ¹⁸⁰⁄₁₁ minutes past 9.

Explanation

In the evening, the Sun is located in the West, so Raja begins by walking toward the West. A first right turn from the West direction points him toward the North. A second right turn from the North direction points him toward the East. Finally, a third right turn from the East direction results in him facing the South.

Explanation

Let the starting point be the origin (0, 0) on a coordinate plane where North is the positive y-axis and East is the positive x-axis. Vivek moves 3 km north to the point (0, 3) and then turns right, which is East, traveling 4 km to reach the final position (4, 3). Ashok moves 5 km west to the point (-5, 0) and then turns right, which is North, traveling 3 km to reach his final position (-5, 3).

To find the distance between Vivek at (4, 3) and Ashok at (-5, 3), use the distance formula d = √((x₂ - x₁)² + (y₂ - y₁)²). Since both individuals are at the same vertical height of 3 km north, the distance is the absolute difference between their horizontal positions: d = |4 - (-5)| = 9 km. Alternatively, substituting into the formula yields d = √((4 - (-5))² + (3 - 3)²) = √(9² + 0²) = 9 km.

Explanation

The word ROAM cannot be formed from the given word MISFORTUNE because it contains the letter A. The source word MISFORTUNE consists of the letters M, I, S, F, O, R, T, U, N, and E. Since the letter A is not present among these letters, ROAM cannot be constructed.

Explanation

The word ROASTING can be formed using the letters available in the word STRANGULATION. The letters required for ROASTING are R, O, A, S, T, I, N, and G. By examining the base word, we find all these letters present: S (1), T (2), R (1), A (2), N (2), G (1), U (1), L (1), I (1), and O (1). Since each letter needed for ROASTING is contained within the parent word in at least the required frequency, the word can be successfully constructed.

Explanation

The coding logic follows a constant shift of two positions backward in the English alphabetical sequence for each letter. Representing the alphabetical position of a letter as n, the coded letter is determined by the position n - 2. In a cyclic alphabet, if the result is less than or equal to 0, 26 is added to find the corresponding letter from the end of the alphabet.

For the word RAMAYANA, the transformation is: R(18) - 2 = 16(P) A(1) - 2 = 25(Y) M(13) - 2 = 11(K) A(1) - 2 = 25(Y) Y(25) - 2 = 23(W) A(1) - 2 = 25(Y) N(14) - 2 = 12(L) A(1) - 2 = 25(Y)

Applying this same rule to the word MAHABHARATA: M(13) - 2 = 11(K) A(1) - 2 = 25(Y) H(8) - 2 = 6(F) A(1) - 2 = 25(Y) B(2) - 2 = 26(Z) H(8) - 2 = 6(F) A(1) - 2 = 25(Y) R(18) - 2 = 16(P) A(1) - 2 = 25(Y) T(20) - 2 = 18(R) A(1) - 2 = 25(Y)

Combining these results gives the coded word KYFYZFYPYRY.

Explanation

The coding scheme follows a simple subtraction rule based on the alphabetical position of each letter. Each letter is replaced by a digit calculated as P - 4, where P represents the numerical position of the letter in the English alphabet (A = 1, B = 2, C = 3, ..., Z = 26).

In the first example, MEKLF corresponds to the positions M(13), E(5), K(11), L(12), and F(6). Subtracting 4 from each position gives 13 - 4 = 9, 5 - 4 = 1, 11 - 4 = 7, 12 - 4 = 8, and 6 - 4 = 2, resulting in the code 91782. In the second example, LLLJK corresponds to L(12), L(12), L(12), J(10), and K(11). Subtracting 4 from these positions yields 12 - 4 = 8, 12 - 4 = 8, 12 - 4 = 8, 10 - 4 = 6, and 11 - 4 = 7, forming the code 88867.

Applying the same logic to the word IGHED, we identify the alphabetical positions as I(9), G(7), H(8), E(5), and D(4). Performing the subtraction P - 4 for each letter gives 9 - 4 = 5, 7 - 4 = 3, 8 - 4 = 4, 5 - 4 = 1, and 4 - 4 = 0. Arranging these digits in order results in the code 53410.

Explanation

The logical deduction follows from the relationship between the sets of radios. Let S be the set of radios sold in the shop, H be the set of high standard radios, and M be the set of Murphy radios. Statement (i) provides that S ⊆ H, and Statement (ii) provides that M ∩ S ≠ ∅. By combining these, we find that the radios in the intersection M ∩ S must also be contained within H because S is a subset of H. Consequently, the intersection M ∩ H is non-empty, confirming that some Murphy radios are of high standard as stated in inference 2. Additionally, since the radios in M ∩ S are confirmed to be high standard, it follows that there exist radios that are simultaneously Murphy radios, high standard, and sold in that shop, which validates inference 4.

Explanation

The population growth follows a pattern where the difference between consecutive terms increases as a sequence of consecutive odd numbers starting from 3. Based on the standard data for this problem, the population values for the initial years are 4, 7, 12, and 19.

The differences between these terms are: 7 - 4 = 3 12 - 7 = 5 19 - 12 = 7

Since the increments are 3, 5, and 7, the next increment in the sequence of consecutive odd numbers is 9. To find the missing population value, this increment is added to the last known term: 19 + 9 = 28

This logic is confirmed by the next term in the series, 39, because adding the next consecutive odd number, 11, to 28 results in 39 (28 + 11 = 39).

Explanation

The given operators are substituted as follows: ÷ becomes -, + becomes ×, - becomes ÷, and × becomes +. Applying these substitutions to the equation 19 ÷ 5 + 4 - 2 × 4 = 13, we get:

19 - 5 × 4 ÷ 2 + 4

Following the BODMAS rule, division is performed first: 4 ÷ 2 = 2 The expression simplifies to 19 - 5 × 2 + 4.

Next, perform multiplication: 5 × 2 = 10 The expression simplifies to 19 - 10 + 4.

Finally, perform addition and subtraction from left to right: 19 - 10 = 9 9 + 4 = 13

The result matches the value on the right-hand side of the equation.

Explanation

The relationship established in the analogy is between a territory and its constitutional or nominal executive head. In the Indian political system, the President is the nominal head of the Country, with executive powers of the Union vested in him under Article 53. Similarly, the Governor acts as the nominal executive head of a State, as provided under Article 153 and Article 154 of the Constitution. Both positions represent the formal authority of their respective jurisdictions while the actual administration is carried out by the Council of Ministers.

Explanation

The relationship in the given pair is based on an optical phenomenon and the specific location or medium where it is typically observed. A mirage is an optical illusion caused by atmospheric conditions, most commonly seen in a desert due to the refraction of light through air layers of different temperatures. Similarly, a rainbow is a meteorological and optical phenomenon caused by the reflection, refraction, and dispersion of light in water droplets, which is observed in the sky.

Explanation

The relationship between the first pair is based on the reversal of the sequence of letters. When the letters of the word TEKCAR are written in reverse order, it forms the word RACKET. Applying this same logic to the second pair, reversing the letters of TCEJBO results in the word OBJECT.

Explanation

The relationship in this analogy is determined by the internal arrangement and alphabetical positions of the letters in each group. Each group follows a specific pattern of n, n-1, n-2, n+1, where n represents the numerical position of the first letter in the alphabet.

JIHK: J is 10, I is 9, H is 8, and K is 11. This follows the sequence 10, 10-1, 10-2, 10+1. PONQ: P is 16, O is 15, N is 14, and Q is 17. This follows the sequence 16, 16-1, 16-2, 16+1. WVUX: W is 23, V is 22, U is 21, and X is 24. This follows the sequence 23, 23-1, 23-2, 23+1.

In each of these sets, the first three letters are in descending alphabetical order, and the fourth letter is the immediate alphabetical successor of the first letter.

Applying this same logic to the answer: MLKN: M is 13, L is 12, K is 11, and N is 14. This follows the sequence 13, 13-1, 13-2, 13+1.

Additionally, each group is a specific permutation of four consecutive letters from the alphabet. For any four consecutive letters (1st, 2nd, 3rd, 4th), the letters are rearranged in the order of 3rd, 2nd, 1st, and 4th. MLKN is the (3, 2, 1, 4) permutation of the consecutive sequence KLMN.

Explanation

The relationship between the first and second letter groups is established by shifting each letter forward by two positions in the English alphabetical order. Applying this logic to the first pair UUWX to WWYZ, we observe: U + 2 = W U + 2 = W W + 2 = Y X + 2 = Z

Following the same pattern for the third group OOQR: O + 2 = Q O + 2 = Q Q + 2 = S R + 2 = T

By incrementing each letter of OOQR by two, the resulting sequence is QQST.

Explanation

The relationship between the first pair of letter groups follows a pattern of increasing positional shifts in the alphabet. For BIMN and CKPR, the logic is as follows: B shifted by 1 position forward becomes C, I shifted by 2 positions forward becomes K, M shifted by 3 positions forward becomes P, and N shifted by 4 positions forward becomes R.

Applying this same logic to the word CURD: C shifted by 1 position forward is D. U shifted by 2 positions forward is W. R shifted by 3 positions forward is U. D shifted by 4 positions forward is H. This transformation results in the sequence DWUH.

Explanation

The relationship between the first and second terms is established by shifting each letter forward by 6 positions in the English alphabetical sequence. Following the alphabetical order where A=1, B=2, and so on:

B (2) + 6 = H (8) C (3) + 6 = I (9) F (6) + 6 = L (12) E (5) + 6 = K (11)

Applying this same logic to the third term NORQ, we shift each letter forward by 6 positions:

N (14) + 6 = 20 (T) O (15) + 6 = 21 (U) R (18) + 6 = 24 (X) Q (17) + 6 = 23 (W)

Combining these results yields the sequence TUXW.

Explanation

The numerical analogy follows the mathematical pattern n² - 1 : n³ - 1. Looking at the second pair 08:26, we can see that 8 = 3² - 1 and 26 = 3³ - 1, where n = 3. Applying this same logic to the first pair ?:63, the second term 63 is equal to 4³ - 1, which identifies n as 4. To find the missing first term, we calculate n² - 1 using n = 4, which results in 4² - 1 = 16 - 1 = 15.

Explanation

The relationship between the numbers in the given pair is established by subtracting the sum of the digits of the first number from the number itself.

For the pair 72:63, the calculation is: 72 - (7 + 2) = 72 - 9 = 63

Applying the same logic to the number 64: 64 - (6 + 4) = 64 - 10 = 54

Explanation

Basketball is the odd one out because it is played by hand and does not require any additional equipment like a bat or club to strike the ball. In contrast, the other three sports belong to the category of bat-and-ball games, where a player uses a specific implement to hit a ball delivered by an opponent.

Explanation

Ravage is the odd word out because it primarily refers to the act of causing extensive physical damage or destruction to a place or thing. In contrast, the other words describe various forms of psychological or emotional pressure, irritation, and suffering inflicted upon a person. Ravage implies a level of physical devastation that distinguishes it from terms focused on mental distress or interpersonal annoyance.

Explanation

The letter group PRSU follows a pattern of positional increments of +2, +1, and +2 between consecutive letters. Specifically, P + 2 = R, R + 1 = S, and S + 2 = U. In contrast, all other options follow a consistent pattern of +2 increments throughout the entire sequence (+2, +2, +2). Because PRSU contains a +1 increment in the middle instead of maintaining the uniform +2 spacing, it is the odd one out.

Explanation

In the letter groups provided, a specific pattern exists between the letters at the first and third positions, as well as the letters at the second and fourth positions. Specifically, the third letter is obtained by moving two steps backward from the first letter, and the fourth letter is obtained by moving two steps backward from the second letter. This can be expressed as 1ˢᵗ letter - 2 = 3ʳᵈ letter and 2ⁿᵈ letter - 2 = 4ᵗʰ letter.

In the case of YDWB, we see Y(25) - 2 = W(23) and D(4) - 2 = B(2). In TKRI, the logic holds with T(20) - 2 = R(18) and K(11) - 2 = I(9). Similarly, in HLFJ, H(8) - 2 = F(6) and L(12) - 2 = J(10). However, in QNOM, while the first part holds true with Q(17) - 2 = O(15), the second part fails because N(14) - 1 = M(13). Since the gap between the second and fourth letters is only one step instead of two, QNOM does not follow the established pattern.

Explanation

Tomato is the only vegetable in the group that grows above the ground as the fruit of the plant. The other three items are modified plant parts that develop and grow entirely beneath the surface of the soil.

Explanation

The number 125 is a perfect cube, as it can be expressed as 5³ (5 × 5 × 5 = 125). In contrast, the other three numbers — 789, 236, and 347 — are not perfect cubes of any natural number. This specific mathematical property distinguishes 125 from the rest of the group.

Explanation

The logic applied in these equations involves taking the product of the digits of each individual number and then summing those products together. For a given expression AB + CD, the result is calculated using the formula (A × B) + (C × D).

In the first case, 94 + 16 is solved as (9 × 4) + (1 × 6) = 36 + 6 = 42. In the second case, 89 + 23 is solved as (8 × 9) + (2 × 3) = 72 + 6 = 78.

Using the same system for the target equation 63 + 45, we calculate the sum of the digit products as follows: (6 × 3) + (4 × 5) = 18 + 20 = 38

Explanation

This analogy represents the relationship between an animal and its characteristic outer body covering. Just as the body of a fish is typically covered and protected by a layer of scales, the body of a bear is covered by a thick layer of dense hair commonly referred to as fur. Fur serves as a primary integumentary system for bears, providing essential thermal insulation and protection from the environment.

Explanation

The relationship in the analogy is between a profession and the primary tool used to perform that work. Just as a writer uses a pen to create their work, an artist uses a brush as their primary tool.

Explanation

The coding logic is based on the rearrangement of the positions of letters in the given word. In the word NUMERAL, the letters are assigned positions from 1 to 7: 1-N, 2-U, 3-M, 4-E, 5-R, 6-A, and 7-L. The coded word UEALRMN is formed by rearranging these positions into the sequence 2-4-6-7-5-3-1.

Applying this same positional transformation to the word ALGEBRA, where the letters are 1-A, 2-L, 3-G, 4-E, 5-B, 6-R, and 7-A, we follow the 2-4-6-7-5-3-1 pattern. Taking the 2nd letter (L), the 4th letter (E), the 6th letter (R), the 7th letter (A), the 5th letter (B), the 3rd letter (G), and the 1st letter (A) in that specific order yields the coded string LERABGA.

Explanation

The relationship between the first and second groups of letters is established by shifting each letter forward by 4 positions in the English alphabetical order. Applying this logic to the first pair:

B (2) + 4 = 6 (F) D (4) + 4 = 8 (H) A (1) + 4 = 5 (E) C (3) + 4 = 7 (G)

Following the same constant shift of +4 for each corresponding letter in the third group NPMO:

N (14) + 4 = 18 (R) P (16) + 4 = 20 (T) M (13) + 4 = 17 (Q) O (15) + 4 = 19 (S)

The resulting sequence is RTQS.

Explanation

The relationship between the first two sets of letters is defined by a consistent forward shift of 9 positions in the English alphabet. By mapping the letters to their numerical values where A=1 and Z=26, the first sequence FGHI corresponds to the numbers 6, 7, 8, and 9. Adding 9 to each of these values results in 15, 16, 17, and 18, which represents the letters OPQR.

Applying this same logic to the sequence BCDE, which corresponds to the numerical values 2, 3, 4, and 5, we perform the following additions: 2 + 9 = 11, which is the letter K. 3 + 9 = 12, which is the letter L. 4 + 9 = 13, which is the letter M. 5 + 9 = 14, which is the letter N.

This calculation yields the sequence KLMN.

Explanation

The relationship between the letter groups is determined by subtracting a constant value of 7 from the alphabetical position of each letter in the first group to obtain the corresponding letter in the second group. For the first pair PNLJ : IGEC, the transformation is as follows: P (16) - 7 = I (9), N (14) - 7 = G (7), L (12) - 7 = E (5), and J (10) - 7 = C (3).

Applying the same pattern to the second pair VTRP, we subtract 7 from each letter position: V (22) - 7 = 15 (O) T (20) - 7 = 13 (M) R (18) - 7 = 11 (K) P (16) - 7 = 9 (I)

This yields the sequence OMKI.

Explanation

The numerical analogy follows the mathematical pattern where the second term is derived by adding 3 to the first term and then multiplying the result by 3. This can be expressed as (x + 3) × 3 = y.

Applying this logic to the first pair: (17 + 3) × 3 = 20 × 3 = 60

Applying the same logic to the second pair: (20 + 3) × 3 = 23 × 3 = 69

Alternatively, the pattern can be viewed as multiplying the number by 3 and then adding 9, which yields the same result: (20 × 3) + 9 = 60 + 9 = 69.

Explanation

The relationship between the numbers in the first pair follows the logic that the second number is the square of the first number incremented by 2. Using the formula y = (x + 2)², we substitute x = 6 to get (6 + 2)² = 8² = 64. Applying the same mathematical logic to the second pair where x = 11, we calculate (11 + 2)² = 13² = 169.

Explanation

The pattern follows a simple arithmetic operation where the first two digits of the three-digit number are treated as a single value and then divided by the third digit. In the first case, 123 results in 4 because 12 ÷ 3 = 4. Applying the same logic to the second case, 726, we divide the first two digits (72) by the third digit (6), which gives 72 ÷ 6 = 12.

Explanation

The flute is classified as a wind instrument or aerophone because it produces sound through the vibration of a column of air when the player blows across an opening. The other three musical instruments are categorized as string instruments or chordophones, as they generate sound through the vibration of taut strings that are plucked, bowed, or struck. This difference in the fundamental mechanism of sound production makes the flute the odd one out.

Explanation

The word sap refers to the act of gradually weakening or draining away energy, strength, or vitality. It describes a process of depletion or exhaustion over time. This word is the odd one out because it represents a slow reduction of power or spirit, whereas the other terms in the group all share a common theme of being sudden, forceful physical movements.

Explanation

The letter sequences in the group follow a pattern where the first and second letters are consecutive, and the third and fourth letters are also consecutive in the English alphabet. This can be represented by the positional relationships P₂ = P₁ + 1 and P₄ = P₃ + 1. In the sequence CABD, the letters correspond to the numerical positions 3, 1, 2, and 4. Calculating the differences shows that the relationship for the first pair is P₂ = P₁ - 2 and for the second pair is P₄ = P₃ + 2. This sequence fails to satisfy the requirement of having two pairs of consecutive letters in increasing alphabetical order.

Explanation

In the sets CAFD, IGLJ, and OMRP, the alphabetical positions of the letters follow a consistent mathematical pattern. For CAFD, the positions are 3, 1, 6, 4, which follows the sequence: 3 - 2 = 1, 1 + 5 = 6, and 6 - 2 = 4. For IGLJ, the positions are 9, 7, 12, 10, following the same sequence: 9 - 2 = 7, 7 + 5 = 12, and 12 - 2 = 10. For OMRP, the positions are 15, 13, 18, 16, also adhering to the sequence: 15 - 2 = 13, 13 + 5 = 18, and 18 - 2 = 16. However, for TSWV, the positions are 20, 19, 23, 22, which follows a different logic of 20 - 1 = 19, 19 + 4 = 23, and 23 - 1 = 22. Thus, it does not conform to the -2, +5, -2 pattern.

Explanation

The number 644 is the odd one out because it is not divisible by 9. According to the divisibility rule for 9, the sum of the digits of a number must be a multiple of 9. For 644, the sum of the digits is 6 + 4 + 4 = 14, which is not divisible by 9. In contrast, the other numbers in the set have digit sums that are multiples of 9, such as 1 + 6 + 2 = 9, 4 + 0 + 5 = 9, and 5 + 6 + 7 = 18.

Explanation

The number 156 is an even number, whereas the other three numbers in the set, 201, 273, and 345, are all odd numbers. In classification and odd-one-out problems, parity is a standard distinguishing feature when all numbers otherwise share a common property, such as divisibility by 3.