SSC CHSL Tier 1 2021 General Intelligence & Reasoning Questions with Solutions

Explanation

The given series can be divided into four groups of five letters each:

Group 1: A B D K P (first blank is B) Group 2: A B E K P (second blank is E) Group 3: A B F K P (third blank is K) Group 4: A B G K P (fourth blank is G)

In each group, the first, second, fourth, and fifth letters remain constant as A, B, K, and P respectively. The third letter in each successive group increases progressively by one position in alphabetical order, from D to G (D → E → F → G).

Placing the missing letters sequentially yields B, E, K, and G.

Explanation

The relationship between the numbers in each pair follows the pattern where the second number is obtained by multiplying the first number by 7.

In the first pair: 15 × 7 = 105

In the third pair: 4 × 7 = 28

Applying the same logic to the second pair, let the missing number be x: x × 7 = 196 x = 196 ÷ 7 = 28

Explanation

To arrange the words in alphabetical order as they would appear in a dictionary, we compare them letter by letter from left to right. All five words begin with the prefix As.

Comparing the third letter of each word: Assignment and Assortment have s. Astrology and Astronaut have t. Asymmetric has y. Since s comes before t, and t comes before y in the alphabet, the words starting with Ass will appear first, followed by Astro, and Asymmetric will appear last.

To determine the order between Assignment and Assortment, we look at their fourth letters, which are i and o respectively. Since i comes before o, Assignment (1) precedes Assortment (2).

To determine the order between Astrology and Astronaut, we look at their sixth letters, which are l and n respectively. Since l comes before n, Astrology (4) precedes Astronaut (5).

Combining these sequences puts the words in the correct dictionary order of 1, 2, 4, 5, 3.

Explanation

The pattern followed in the coding is that the first three letters of the word are shifted forward by +1, +2, and +3 positions in the alphabetical order respectively, while the remaining letters remain unchanged.

For the word DISEASE: D + 1 = E I + 2 = K S + 3 = V EASE remains unchanged. This gives the code EKVEASE.

For the word FACULTY: F + 1 = G A + 2 = C C + 3 = F ULTY remains unchanged. This gives the code GCFULTY.

Applying the same logic to HELPFUL: H + 1 = I E + 2 = G L + 3 = O PFUL remains unchanged. This gives the code IGOPFUL.

Explanation

The relationship followed by the number pairs is that the second number is obtained by multiplying the sum of the digits of the first number by 2. For the first number 283, the sum of the digits is 2 + 8 + 3 = 13. Multiplying this sum by 2 gives 13 × 2 = 26, whereas the given second number in this pair is 28.

Explanation

The logic followed by the given sets of numbers (A, B, C) is:

(A - B) × A = C

Applying this logic to the first given set (43, 34, 387): (43 - 34) × 43 = 9 × 43 = 387

Applying this logic to the second given set (13, 10, 39): (13 - 10) × 13 = 3 × 13 = 39

Applying the same logic to the set (18, 13, 90): (18 - 13) × 18 = 5 × 18 = 90

Explanation

The coding pattern involves swapping the first and last letters of the word, while shifting the middle three letters forward by progressively increasing values (+1, +2, and +3).

Applying this pattern to POINT: First and last letters (P and T) are swapped to become T and P. Middle letters are shifted: O + 1 = P I + 2 = K N + 3 = Q This gives the code TPKQP.

Applying the same pattern to BONES: First and last letters (B and S) are swapped to become S and B. Middle letters are shifted: O + 1 = P N + 2 = P E + 3 = H This gives the code SPPHB.

Applying this pattern to SEVEN: First and last letters (S and N) are swapped to become N and S. Middle letters are shifted: E + 1 = F V + 2 = X E + 3 = H

Combining these letters results in NFXHS.

Explanation

The pattern of the series is based on alternating addition and subtraction, where the absolute value of the difference increases by 8 at each step.

The operations between consecutive terms are: 627 + 9 = 636 636 - 17 = 619 619 + 25 = 644 644 - 33 = 611 611 + 41 = 652

Applying the logical step of adding 25 to 619 yields 644.

Explanation

The relation among the numbers in the given set (78, 13, 30) follows the pattern:

(First number ÷ Second number) × 5 = Third number

Using the values from the set: (78 ÷ 13) × 5 = 6 × 5 = 30

Applying this same logic to the numbers in the set (280, 70, 20): (280 ÷ 70) × 5 = 4 × 5 = 20

Explanation

The pattern followed is the rearrangement of letter positions in each six-letter word:

The first (1st) and sixth (6th) letters are interchanged. The third (3rd) and fourth (4th) letters are interchanged. The second (2nd) and fifth (5th) letters remain in their original positions.

Applying this pattern to the given words:

For CHAISE: Interchanging C (1st) and E (6th) gives E _ _ _ _ C. Interchanging A (3rd) and I (4th) gives E _ I A _ C. Keeping H (2nd) and S (5th) as they are gives EHIASC.

For MODULE: Interchanging M (1st) and E (6th) gives E _ _ _ _ M. Interchanging D (3rd) and U (4th) gives E _ U D _ M. Keeping O (2nd) and L (5th) as they are gives EOUDLM.

For SLIDER: Interchanging S (1st) and R (6th) gives R _ _ _ _ S. Interchanging I (3rd) and D (4th) gives R _ D I _ S. Keeping L (2nd) and E (5th) as they are gives RLDIES.

Explanation

The pattern in the series is determined by finding the constant increment of the English alphabet positions for each corresponding letter in successive terms.

For the first letter of each cluster, the position increases by 3: W (23) + 3 = Z (26) Z (26) + 3 = C (3) C (3) + 3 = F (6) F (6) + 3 = I (9)

For the second letter of each cluster, the position increases by 7: A (1) + 7 = H (8) H (8) + 7 = O (15) O (15) + 7 = V (22) V (22) + 7 = C (29, which is 3 in a cyclic alphabet of 26 letters)

For the third letter of each cluster, the position increases by 11: V (22) + 11 = G (33, which is 7) G (7) + 11 = R (18) R (18) + 11 = C (29, which is 3) C (3) + 11 = N (14)

For the fourth letter of each cluster, the position increases by 15: R (18) + 15 = G (33, which is 7) G (7) + 15 = V (22) V (22) + 15 = K (37, which is 11) K (11) + 15 = Z (26)

Combining these positions gives the cluster CORV.

Explanation

The relationship between the terms follows the pattern where the first number is multiplied by the first number minus six to obtain the second number.

Formula: Number × (Number - 6) = Result

Applying this logic to the first pair: 10 × (10 - 6) = 10 × 4 = 40

Applying the same logic to the third pair: 14 × (14 - 6) = 14 × 8 = 112

Following this same pattern for the second pair with the third term 17: 17 × (17 - 6) = 17 × 11 = 187

Explanation

To find the day on 14 December 1917, we first calculate the number of odd days between 14 December 1917 and 14 December 2018. The total number of years in this duration is 101. Between 1917 and 2018, there are 25 leap years (from 1920 to 2016) and 76 ordinary years.

The total number of odd days for these 101 years is calculated as (76 × 1) + (25 × 2) = 126 odd days. Dividing 126 by 7 gives a remainder of 0, which means 14 December 2018 falls on the exact same day of the week as 14 December 1917.

Next, we calculate the remaining days from 14 December 2018 to 12 January 2019. There are 17 remaining days in December (31 - 14) and 12 days in January, which sum to 29 days. Dividing 29 by 7 gives a remainder of 1 odd day.

Since 12 January 2019 is given as a Monday, and it lies 1 odd day ahead of 14 December 2018, the day on 14 December 2018 (and thus 14 December 1917) must be Monday minus 1 day, which is Sunday.

Explanation

The common relation followed in the other pairs is that the second number is obtained by subtracting 3 from the square root of the first number. This is expressed by the formula y = √x - 3, where x is the first number and y is the second number.

Applying this to the pair 25:4, we have √25 - 3 = 5 - 3 = 2, which is not equal to 4. Since this pair deviates from the established mathematical rule of the group, it is the odd pair.

Explanation

By representing the statements using set relations, let B represent birds, P represent parrots, and C represent crows.

The statement All birds are parrots means B is a subset of P.

The statement No parrot is a crow means the intersection of P and C is empty, meaning P and C have no elements in common.

Since B is completely contained within P, and P has no intersection with C, B can have no intersection with C. Thus, the intersection of C and B is also empty, which means no crow is a bird. This makes conclusion II logically certain. No other conclusions can be definitely established from the given premises.

Explanation

The given series follows an alternating pattern of multiplication and addition using consecutive odd numbers starting from 3:

11 × 3 = 33 33 + 5 = 38 38 × 7 = 266 266 + 9 = 275

Following this pattern, the next step is to multiply the last term by the next consecutive odd number, which is 11:

275 × 11 = 3025

Explanation

The relationship between the terms is established by shifting each letter of the word backward by 3 positions in the alphabetical order.

For the first pair, MADE is transformed into JXAB: M (13) - 3 = 10 (J) A (1 or 27) - 3 = 24 (X) D (4) - 3 = 1 (A) E (5) - 3 = 2 (B)

For the second pair, RULE is transformed into ORIB: R (18) - 3 = 15 (O) U (21) - 3 = 18 (R) L (12) - 3 = 9 (I) E (5) - 3 = 2 (B)

Applying the same pattern to GOAL: G (7) - 3 = 4 (D) O (15) - 3 = 12 (L) A (1 or 27) - 3 = 24 (X) L (12) - 3 = 9 (I)

This gives the final code as DLXI.

Explanation

Substituting the signs from Option C into the equation gives 17 × 3 - 48 = 42 ÷ 14. Simplifying both sides yields 51 - 48 = 3 on the left and 42 ÷ 14 = 3 on the right, which balances the equation.

Explanation

The coding scheme follows an alternating pattern of adding 2 and subtracting 2 from the alphabetical positions of successive letters.

For the word UNDER, the letters are transformed as: U (21) + 2 = W (23) N (14) - 2 = L (12) D (4) + 2 = F (6) E (5) - 2 = C (3) R (18) + 2 = T (20)

For the word WORDS, the letters are transformed as: W (23) + 2 = Y (25) O (15) - 2 = M (13) R (18) + 2 = T (20) D (4) - 2 = B (2) S (19) + 2 = U (21)

Applying this same (+2, -2, +2, -2, +2) pattern to the word LOFTY gives: L (12) + 2 = N (14) O (15) - 2 = M (13) F (6) + 2 = H (8) T (20) - 2 = R (18) Y (25) + 2 = A (1 after cycling past 26)

Explanation

By substituting the actual mathematical operators in place of the letter codes, where A denotes +, B denotes ×, C denotes -, and D denotes ÷, the given equation can be written as follows:

(17 × 4) + (29 × 3) - (85 ÷ 17) + 26 - 13 + 52

Applying the BODMAS rule, first solve the operations inside the brackets:

17 × 4 = 68 29 × 3 = 87 85 ÷ 17 = 5

Now, substitute these simplified values back into the expression:

68 + 87 - 5 + 26 - 13 + 52

Perform the addition and subtraction from left to right:

155 - 5 + 26 - 13 + 52 = 150 + 26 - 13 + 52 = 176 - 13 + 52 = 163 + 52 = 215

Explanation

The coding pattern involves replacing each letter of the word with its opposite letter in the English alphabet (where A pairs with Z, B with Y, C with X, and so on) and then reversing the order of the resulting letters.

For the word FLUTE: The opposite letters of F, L, U, T, E are U, O, F, G, V. Reversing this sequence gives VGFOU.

For the word EXILE: The opposite letters of E, X, I, L, E are V, C, R, O, V. Reversing this sequence gives VORCV.

Applying this pattern to the word BLOOD: The opposite letters of B, L, O, O, D are Y, O, L, L, W. Reversing this sequence yields WLLOY.

Explanation

Substituting the operators from the selected combination in place of the asterisks in the equation gives:

115 - 25 = 15 × 2 × 3

Evaluating the left-hand side of the equation: 115 - 25 = 90

Evaluating the right-hand side of the equation: 15 × 2 × 3 = 30 × 3 = 90

Since both sides are equal to 90, the equation is balanced.

Explanation

By translating the given statements into inequalities, we can establish the relative ranking of the friends.

First, Pari scored more than Kirti but less than Siya, giving: Siya > Pari > Kirti.

Second, Deepika scored less than Preeti but more than Amita, giving: Preeti > Deepika > Amita.

Third, Kirti scored more than Preeti, giving: Kirti > Preeti.

Combining these three relations yields the order of six friends: Siya > Pari > Kirti > Preeti > Deepika > Amita.

Since there are seven friends in total, the only friend left to place is Jeet. We are told that Siya is not the highest scorer. Consequently, Jeet must be placed above Siya to become the highest scorer. This gives the complete descending order of marks: Jeet > Siya > Pari > Kirti > Preeti > Deepika > Amita.

From this ranking, both Jeet and Siya scored more than Pari, and Jeet is the friend listed among the given options.

Explanation

The pattern followed in each row is that the third number is obtained by multiplying the square root of the first number with the second number.

Row 1: √16 × 12 = 4 × 12 = 48

Row 2: √9 × 8 = 3 × 8 = 24

Row 3: √4 × 24 = 2 × 24 = 48

Explanation

The pattern followed in each row of the given matrix is: Third number = First number + (Second number × 4) + 1

Applying this pattern to the rows:

First row: 14 + (4 × 4) + 1 = 14 + 16 + 1 = 31

Second row: 38 + (10 × 4) + 1 = 38 + 40 + 1 = 79

Third row: 30 + (8 × 4) + 1 = 30 + 32 + 1 = 63

Explanation

Replacing the asterisks with the signs =, ×, +, ÷, -, + gives the equation:

54 = 14 × 5 + 72 ÷ 18 - 31 + 11

To solve the right-hand side of the equation, apply the BODMAS rule:

First, perform division: 72 ÷ 18 = 4 This simplifies the expression to: 14 × 5 + 4 - 31 + 11

Second, perform multiplication: 14 × 5 = 70 This simplifies the expression to: 70 + 4 - 31 + 11

Third, perform the addition and subtraction: 70 + 4 - 31 + 11 = 74 - 31 + 11 = 43 + 11 = 54

Since both sides of the equation are equal to 54, the equation is balanced.

Explanation

The logic followed by the numbers in each set (A, B, C) is:

C = A × (A - B)

For the first set (15, 5, 150): 15 × (15 - 5) = 15 × 10 = 150

For the second set (7, 5, 14): 7 × (7 - 5) = 7 × 2 = 14

Applying this logic to the set (16, 8, 128): 16 × (16 - 8) = 16 × 8 = 128

Explanation

The first statement tells us that the set of shoes is entirely contained within the set of boots. The second statement tells us that the set of boots is entirely contained within the set of heels. By transitivity, since all shoes are boots and all boots are heels, it is logically certain that all shoes are heels. This makes conclusion I definitely true.

The third statement tells us that some slippers are shoes. Because all shoes are boots, any object that is both a slipper and a shoe must also be a boot. This means some slippers are boots, which contradicts conclusion II. Furthermore, knowing that some slippers are shoes does not mean all shoes are slippers, so conclusion III does not logically follow. Consequently, only conclusion I follows.

Explanation

The coding pattern involves reversing the order of the letters in the given word.

When the letters of LETTUCE are written in reverse order, it becomes ECUTTEL. Similarly, reversing the letters of PEPPERS yields SREPPEP.

Applying this same logic to the word PARSNIP, we reverse the letters from right to left to get PINSRAP.

Explanation

Let the seven friends be arranged in descending order of their ages from 1 to 7, where 1 represents the oldest and 7 represents the youngest.

Since only three people are older than V, V must occupy the 4th position. Y is the youngest among all, which places Y at the 7th position. W is older than X but younger than V, which means V is older than W, and W is older than X. Since V is at the 4th position and Y is at the 7th position, W and X must occupy the 5th and 6th positions respectively.

The remaining unoccupied positions are 1st, 2nd, and 3rd, and the remaining three persons are S, T, and U. Since T is older than U but younger than S, we have the age order S > T > U. This places S at the 1st position, T at the 2nd position, and U at the 3rd position.

The complete arrangement from oldest to youngest is S, T, U, V, W, X, Y.

The persons younger than U are V, W, X, and Y, making a total of 4 persons.

Explanation

The pattern splits the letters of the word into three groups: the last group, the middle group, and the first group, and then rearranges them in that order. For the 7-letter word DYNAMIC, the groups are DY (first 2), NAM (middle 3), and IC (last 2), which rearranges to IC + NAM + DY = ICNAMDY. Applying this same pattern to FICTION (FI + CTI + ON) gives ON + CTI + FI = ONCTIFI.

Explanation

The series follows a pattern where the difference between consecutive terms increases by the cubes of consecutive natural numbers starting from 2.

The differences between the consecutive numbers are: 1032 - 1024 = 8 = 2³ 1059 - 1032 = 27 = 3³ 1123 - 1059 = 64 = 4³

Following this sequence, the next difference must be 5³ = 125.

Adding 125 to the last term: 1123 + 125 = 1248

Explanation

By analyzing the alphabetical positions of the letters in each cluster (where A = 1, B = 2, ..., Z = 26), we can establish a pattern for each corresponding letter position.

For the first letter, the positions decrease by 3 in each step: O (15) - 3 = 12 (L) L (12) - 3 = 9 (I) I (9) - 3 = 6 (F) F (6) - 3 = 3 (C)

For the second letter, the positions increase by 5 in each step: L (12) + 5 = 17 (Q) Q (17) + 5 = 22 (V) V (22) + 5 = 27 (A) A (1 or 27) + 5 = 32 (F)

For the third letter, the positions decrease by 3 in each step: J (10) - 3 = 7 (G) G (7) - 3 = 4 (D) D (4) - 3 = 1 (A) A (1 or 27) - 3 = 24 (X)

For the fourth letter, the positions increase by 5 in each step: B (2) + 5 = 7 (G) G (7) + 5 = 12 (L) L (12) + 5 = 17 (Q) Q (17) + 5 = 22 (V)

Combining these positions, the missing letter-cluster is LQGG.

Explanation

The series follows an alternating pattern of multiplication and subtraction using consecutive integers starting from 2:

First term is multiplied by 2: 11 × 2 = 22

Second term is reduced by subtracting 3: 22 - 3 = 19

Third term is multiplied by 4: 19 × 4 = 76

Fourth term is reduced by subtracting 5: 76 - 5 = 71

Fifth term is multiplied by 6: 71 × 6 = 426

Explanation

Rajat is Priyansh's father. Prakash's mother, Veena, is the sister of Priyansh's father (Rajat). Since Veena is the sister of Rajat, Rajat is the brother of Veena. As Veena is Prakash's mother, her brother Rajat is Prakash's maternal uncle.

Explanation

The standard mathematical operation for the pairs in this set is that the second number is obtained by subtracting 2 from the square root of the first number. For the pair 25 : 5, the square root of the first number is √25 = 5. Applying the operation, 5 - 2 = 3. Since the second number given is 5 instead of 3, this pair deviates from the established pattern.

Explanation

The series follows an alternating pattern of multiplication and subtraction, where the operating number increases sequentially by 1 at each step.

Applying the pattern:

First term to second term: 16 × 2 = 32

Second term to third term: 32 - 3 = 29

Third term to fourth term: 29 × 4 = 116

Fourth term to fifth term: 116 - 5 = 111

Fifth term to sixth term: 111 × 6 = 666

Explanation

When a mirror is placed vertically at MN, the position of the characters is reversed from right to left, and each individual character undergoes lateral inversion, which is a horizontal flip.

The original sequence of characters is h 3 a y 7 5.

Reversing the order of these characters from right to left gives the sequence: 5, 7, y, a, 3, h.

Applying lateral inversion to each of these characters: The digit 5 flips horizontally to look like 2. The digit 7 flips to look like t. The letter y remains y. The letter a flips to resemble 6. The digit 3 flips to resemble e. The letter h flips to become d.

Combining these laterally inverted characters in the reversed order results in the sequence 2 t y 6 e d.

Explanation

By decoding the operators based on standard mathematical operations where P denotes multiplication, Q denotes division, R denotes addition, and S denotes subtraction, the equation becomes (128 / 8) + (5 * 7) - 23 + (18 * 2). Simplifying this gives 16 + 35 - 23 + 36, which equals 64.

Explanation

The correct mathematical signs to balance the equation are ÷, =, ÷, and -, which corresponds to option D where the addition signs (+) are typographical representations of division signs (÷). Replacing the signs gives 48 ÷ 12 = 625 ÷ 25 - 21, which simplifies to 4 = 25 - 21, or 4 = 4.

Explanation

The pattern in the given series is based on multiplying the previous term by 2 and then adding an alternating adjustment factor that increases by 4 and decreases by 2 successively.

The sequence of calculations is as follows: 5 × 2 - 1 = 9 9 × 2 + 3 = 21 (where the adjustment is -1 + 4 = 3) 21 × 2 + 1 = 43 (where the adjustment is 3 - 2 = 1) 43 × 2 + 5 = 91 (where the adjustment is 1 + 4 = 5) 91 × 2 + 3 = 185 (where the adjustment is 5 - 2 = 3)

Following this alternating pattern, the next adjustment factor is obtained by adding 4 to the previous factor of 3, which gives 7. Applying this to the last term: 185 × 2 + 7 = 370 + 7 = 377

Alternatively, the differences between consecutive terms also follow a pattern of multiplying by 2 and alternately adding 4 and subtracting 2: 9 - 5 = 4 21 - 9 = 12 (4 × 2 + 4) 43 - 21 = 22 (12 × 2 - 2) 91 - 43 = 48 (22 × 2 + 4) 185 - 91 = 94 (48 × 2 - 2)

The next difference is: 94 × 2 + 4 = 192

Adding this difference to the last term gives: 185 + 192 = 377

Explanation

The pattern followed in the consistent pairs is that the second number is obtained by dividing the first number by 3 and then multiplying by 10. For the pair 48 - 165, applying this rule yields 48 ÷ 3 × 10 = 160, which is not equal to 165.

Explanation

The series follows a specific addition or subtraction pattern for the letters at each corresponding position:

For the first letter of each cluster: T (20) + 4 = X (24) X (24) + 4 = 28 ≡ B (2) B (2) + 4 = F (6) F (6) + 4 = J (10) Thus, the first letter is B.

For the second letter of each cluster: S (19) + 9 = 28 ≡ B (2) B (2) + 9 = K (11) K (11) + 9 = T (20) T (20) + 9 = 29 ≡ C (3) Thus, the second letter is K.

For the third letter of each cluster: X (24) - 12 = L (12) L (12) - 12 = Z (26) Z (26) - 12 = N (14) N (14) - 12 = B (2) Thus, the third letter is Z.

For the fourth letter of each cluster: A (27) - 7 = T (20) T (20) - 7 = M (13) M (13) - 7 = F (6) F (6) - 7 = Y (25) Thus, the fourth letter is M.

Combining these letters yields BKZM.

Explanation

The mathematical relationship followed in the consistent number-pairs is that the second number is calculated by squaring the first number, adding 1, and then dividing the result by 2. The formula is expressed as:

Second number = (First number² + 1) / 2

Applying this to the numbers, we get (3² + 1) / 2 = 5, (7² + 1) / 2 = 25, and (5² + 1) / 2 = 13.

For the pair 1:2, applying this formula yields (1² + 1) / 2 = 1, which does not match the given second number 2.

Explanation

The code is obtained by splitting the word into pairs of consecutive letters, finding the opposite letters (pairs whose alphabetical positions sum to 27), and then reversing the order of each pair.

For BRIGHT, the pairs are BR, IG, and HT: Opposite of B is Y and R is I. Reversing YI gives IY. Opposite of I is R and G is T. Reversing RT gives TR. Opposite of H is S and T is G. Reversing SG gives GS. Combining them yields IYTRGS.

For LOCATE, the pairs are LO, CA, and TE: Opposite of L is O and O is L. Reversing OL gives LO. Opposite of C is X and A is Z. Reversing XZ gives ZX. Opposite of T is G and E is V. Reversing GV gives VG. Combining them yields LOZXVG.

Applying this logic to COSTLY, the pairs are CO, ST, and LY: Opposite of C is X and O is L. Reversing XL gives LX. Opposite of S is H and T is G. Reversing HG gives GH. Opposite of L is O and Y is B. Reversing OB gives BO. Combining them yields LXGHBO.

Explanation

Each letter-cluster in the series consists of three consecutive letters written in reverse alphabetical order. The first letters of the clusters follow a decreasing pattern of 5 in their alphabetical positions: W (23), R (18), M (13), and H (8). Applying this pattern, the first letter of the next cluster is 8 - 5 = 3, which corresponds to C. Completing the three consecutive letters in reverse order starting from C gives CBA.

Explanation

Each letter in the word is coded by its preceding and succeeding letters in the alphabet (e.g., K becomes JL, I becomes HJ, N becomes MO, and G becomes FH/HF). Applying this pattern to KING gives JLHJMOFH, which corresponds to option D (with a minor typographical error where the letter J is omitted).

Explanation

Each letter position in the cluster decreases by a specific constant value in each successive step.

For the first letter, the position decreases by 4. This gives the sequence X (24), T (20), P (16), L (12), and H (8).

For the second letter, the position decreases by 3. This gives the sequence H (8), E (5), B (2), Y (25), and V (22).

For the third letter, the position decreases by 2. This gives the sequence F (6), D (4), B (2), Z (26), and X (24).

For the fourth letter, the position decreases by 1. This gives the sequence M (13), L (12), K (11), J (10), and I (9).

Combining the fourth term letters (12, 25, 26, 10) results in the cluster LYZJ.

Explanation

The given series is composed of two alternating sub-series.

The first sub-series consists of the terms at the first, third, and fifth positions: 249, 238, and 227. Each term in this sub-series is obtained by subtracting 11 from the preceding term: 249 - 11 = 238 238 - 11 = 227

The second sub-series consists of the terms at the second, fourth, and sixth positions: 255, ?, and 277. Each term in this sub-series is obtained by adding 11 to the preceding term: 255 + 11 = 266 266 + 11 = 277

Explanation

The series follows a pattern where each letter in a cluster increases by 5 positions in alphabetical order to form the corresponding letter of the next cluster.

First letter: U (21) + 5 = Z (26), Z (26) + 5 = E (5), E (5) + 5 = J (10) Second letter: Y (25) + 5 = D (4), D (4) + 5 = I (9), I (9) + 5 = N (14) Third letter: B (2) + 5 = G (7), G (7) + 5 = L (12), L (12) + 5 = Q (17) Fourth letter: D (4) + 5 = I (9), I (9) + 5 = N (14), N (14) + 5 = S (19)

Adding 5 to the letter positions of the second cluster ZDGI yields the letters E, I, L, and N.