IBPS RRB Clerk Prelims 2016 Numerical Ability Questions with Solutions

Explanation

The total price of 10 books is 10 × 12 = ₹120, and the total price of 8 books is 8 × 11.75 = ₹94. The combined price of the remaining 2 books is 120 - 94 = ₹26. Letting the price of one book be x, the other book costs 1.6x. Solving x + 1.6x = 26 gives 2.6x = 26, so x = ₹10 and 1.6x = ₹16.

Explanation

Let the initial number of men be M. After 15 days, provisions remain for M men for 45 days. Adding 500 men makes the total (M + 500) men, and the provision lasts for 40 days. Equating total man-days gives M × 45 = (M + 500) × 40, which simplifies to 45M = 40M + 20000, giving 5M = 20000, or M = 4000.

Explanation

Let the marked price be 100. With a 10% commission, the selling price is 90, which yields a 20% gain, making the cost price 90 / 1.20 = 75. When the commission is increased to 15%, the new selling price becomes 85. The new gain is 85 - 75 = 10, and the new gain percentage is (10 / 75) × 100 = 40/3%.

Explanation

A dozen contains 12 mirrors, so the number of broken and unbroken mirrors must be non-negative integers summing to 12. Therefore, the sum of the terms in the ratio must divide 12 evenly.

Sum of ratio terms: 7 + 5 = 12 (12 ÷ 12 = 1, valid) 3 + 1 = 4 (12 ÷ 4 = 3, valid) 3 + 2 = 5 (12 ÷ 5 = 2.4, invalid) 2 + 1 = 3 (12 ÷ 3 = 4, valid)

The ratio 3:2 yields fractional values of mirrors and is impossible.

Explanation

Let the number of ₹1, 50-paisa (₹0.50), and 25-paisa (₹0.25) coins be 2x, 3x, and 4x respectively.

Total value = 2x(1) + 3x(0.50) + 4x(0.25) = 2x + 1.5x + x = 4.5x Given total value = ₹216

4.5x = 216 x = 216 / 4.5 = 48

Number of 50-paisa coins = 3x = 3 × 48 = 144.

Explanation

Since B is 3 times as fast as C, the ratio of speeds of B and C is 3 : 1.

For a fixed distance, time taken is inversely proportional to speed. Time taken by B = (Time taken by C) / 3 = 42 / 3 = 14 min.

Explanation

Cost Price of 2 dozen (24 mangoes) = ₹32.

Revenue from selling 18 mangoes (1.5 dozen) at ₹12 per dozen = 1.5 × 12 = ₹18. Revenue from selling remaining 6 mangoes (0.5 dozen) at ₹4 per dozen = 0.5 × 4 = ₹2. Total Selling Price = 18 + 2 = ₹20.

Loss = Cost Price - Selling Price = 32 - 20 = ₹12. Loss percentage = (12 / 32) × 100 = 37.5%.

Explanation

Cost price of mixture = Selling Price / (1 + Profit%) = 9.24 / 1.10 = ₹8.40 per kg.

Using alligation for sugar at ₹9/kg and sugar at ₹7/kg: Ratio of quantity = (8.40 - 7) : (9 - 8.40) = 1.40 : 0.60 = 7 : 3.

Let the required quantity of sugar at ₹9/kg be x kg. x / 27 = 7 / 3 x = 27 × (7 / 3) = 63 kg.