#ibps rrb
- The average of five numbers is 42. When one number is removed, the average of the remaining four numbers becomes 40. What is the number removed? Answer: D. 50 Answer: (D) 50 Sum of five = 210, sum of four = 160. Removed number = 210 − 160 = 50. 1
- A shopkeeper marks an article 25% above its cost price and allows a discount of 12% on the marked price. What is his profit percentage? Answer: C. 10% Answer: (C) 10% Take CP = 100. MP = 125, SP = 125 × 0.88 = 110. Profit = 10%. 1
- The difference between the compound interest (compounded annually) and the simple interest on a sum for 2 years at 10% per annum is Rs. 75. What is the sum (in Rs.)? Answer: C. 7500 Answer: (C) 7500 For 2 years, CI − SI = P(R/100)² . So 75 = P × 0.01 , P = Rs. 7,500. 1
- A invests Rs. 12,000 in a business for 12 months and B invests Rs. 20,000 for 9 months. Out of a total profit of Rs. 13,500, what is B's share (in Rs.)? Answer: C. 7500 Answer: (C) 7500 Ratio = 12000 × 12 : 20000 × 9 = 144000 : 180000 = 4 : 5. B's share = 5/9 × 13500 = 7500 . 1
- A 60-litre mixture contains milk and water in the ratio 7 : 3. How many litres of water must be added to make the ratio 3 : 2? Answer: D. 10 Answer: (D) 10 Milk = 42 L, water = 18 L. Need 42 : (18 + w) = 3 : 2, so 18 + w = 28 and w = 10 L. 1
- A can finish a work in 12 days and B in 18 days. They work together for 4 days, after which A leaves. In how many more days will B finish the remaining work? Answer: D. 8 Answer: (D) 8 In 4 days they do 4(1/12+1/18) = 5/9 . Remaining 4/9 at B's rate 1/18 takes 8 days. 1
- Pipes A and B can fill a tank in 20 minutes and 30 minutes respectively, and pipe C can empty the full tank in 15 minutes. If all three pipes are opened together on an empty tank, in how many minutes will it be filled? Answer: D. 60 Answer: (D) 60 Net rate = 1/20+1/30-1/15 = 3+2-4/60 = 1/60 . Time = 60 minutes. 1
- A 240 m long train crosses a pole in 12 seconds. How long (in seconds) will it take to cross a 360 m long platform? Answer: D. 30 Answer: (D) 30 Speed = 240 ÷ 12 = 20 m/s. Distance to cover = 240 + 360 = 600 m. Time = 600 ÷ 20 = 30 s. 1
- A boat covers 48 km downstream in 3 hours and 32 km upstream in 4 hours. What is the speed of the boat in still water (in km/h)? Answer: B. 12 Answer: (B) 12 Downstream speed = 16 km/h, upstream = 8 km/h. Speed in still water = (16 + 8) ÷ 2 = 12 km/h. 1
- The present ages of A and B are in the ratio 5 : 7. Six years ago, their ages were in the ratio 2 : 3. What is B's present age (in years)? Answer: D. 42 Answer: (D) 42 Let ages be 5k and 7k. 5k-6/7k-6 = 2/3 ⇒ 15k - 18 = 14k - 12 ⇒ k = 6 . B = 42 years. 1
- A bag contains 5 red, 4 blue and 3 green balls. Two balls are drawn at random together. What is the probability that both balls are of the same colour? Answer: B. 19/66 Answer: (B) 19/66 Favourable = binom52+binom42+binom32 = 10+6+3 = 19 . Total = binom122 = 66 . Probability = 19/66. 1
- The perimeter of a rectangle is 64 cm and its length is 6 cm more than its breadth. What is its area (in sq cm)? Answer: C. 247 Answer: (C) 247 l + b = 32 and l − b = 6, so l = 19 cm, b = 13 cm. Area = 19 × 13 = 247 sq cm. 1
- In an election between two candidates, the winner got 58% of the valid votes and won by 2,400 votes. What was the total number of valid votes? Answer: A. 15000 Answer: (A) 15000 Margin = 58% − 42% = 16% of valid votes = 2400. Valid votes = 2400 ÷ 0.16 = 15,000. 1
- A trader sells two mobile phones for Rs. 1,200 each. On one he gains 20% and on the other he loses 20%. What is his overall gain or loss percentage? Answer: A. 4% loss Answer: (A) 4% loss CPs: 1200 ÷ 1.2 = 1000 and 1200 ÷ 0.8 = 1500. Total CP = 2500, total SP = 2400. Loss = 100, i.e. 100/... 1
- A car goes from town P to town Q, 120 km apart, at 40 km/h and returns from Q to P at 60 km/h. What is its average speed for the whole journey (in km/h)? Answer: C. 48 Answer: (C) 48 Time = 120/40 + 120/60 = 3 + 2 = 5 h for 240 km. Average speed = 240 ÷ 5 = 48 km/h. 1
- What will come in place of the question mark (?)?\( 35\% \text{ of } 640 + 18^2 - 25 \times 6 = ? \) Answer: C. 398 Answer: (C) 398 224 + 324 - 150 = 398 . 1
- What will come in place of the question mark (?)?\( \left(\tfrac{3}{4} \text{ of } 896\right) \div 12 + ? = 85 \) Answer: D. 29 Answer: (D) 29 3/4 × 896 = 672;\ 672 ÷ 12 = 56;\ ? = 85 - 56 = 29 . 1
- What will come in place of the question mark (?)?\( \sqrt{1764} + 3^3 \times 4 - 15\% \text{ of } 300 = ? \) Answer: A. 105 Answer: (A) 105 42 + 108 - 45 = 105 . 1
- What will come in place of the question mark (?) in the series?7, 15, 31, 63, 127, ? Answer: B. 255 Answer: (B) 255 Each term = previous × 2 + 1. 127 × 2 + 1 = 255. 1
- What will come in place of the question mark (?) in the series?4, 6, 12, 30, 90, ? Answer: C. 315 Answer: (C) 315 Multipliers are ×1.5, ×2, ×2.5, ×3, ×3.5. 90 × 3.5 = 315. 1
- What will come in place of the question mark (?) in the series?11, 13, 17, 25, 41, ? Answer: C. 73 Answer: (C) 73 Differences are 2, 4, 8, 16, so the next difference is 32: 41 + 32 = 73. 1
- What will come in place of the question mark (?) in the series?2, 9, 28, 65, 126, ? Answer: A. 217 Answer: (A) 217 Terms are n³ + 1 : 1+1, 8+1, 27+1, 64+1, 125+1, so next is 6³ + 1 = 217 . 1
- Find the wrong number in the series.5, 12, 26, 54, 112, 222 Answer: C. 112 Answer: (C) 112 Each term = previous × 2 + 2: 5, 12, 26, 54, 110, 222. So 112 is wrong; it should be 110. 1
- A man is facing South. He turns 135° clockwise and then 90° anticlockwise. Which direction is he facing now? Answer: D. South-West Answer: (D) South-West South = 180°. 135° clockwise → 315° (North-West). 90° anticlockwise → 225°, which is South-West... 1