Quantitative Aptitude — MCQ Practice Questions & Answers

Question 1

A can complete a work in 20 days. How much work will A complete in 5 days?

Accepted Answer

Correct answer: B. 1/4 — This question tests the concept of work rate and how much work is completed in a given time period. Step 1: Find A's work rate per day A completes the entire work in 20 days, so the work rate is 1 part per day. 	ext{Work rate} = \frac{1}{20} 	ext{ work per day} Step 2: Calculate work completed in 5 days Multiply the daily work rate by the number of days. 	ext{Work completed} = \frac{1}{20} 	imes 5 = \frac{5}{20} Step 3: Simplify the fraction Reduce the fraction to its simplest form by dividing both numerator and denominator by 5. \frac{5}{20} = \frac{1}{4} A will complete 1/4 of the work in 5 days.

Answer

A. 1/5

Answer

C. 1/3

Answer

D. 1/2

Question 2

B can do a job in 15 days. What is B's work rate per day?

Accepted Answer

Correct answer: B. 1/15 — This question asks us to find B's daily work rate when the total job can be completed in 15 days. Step 1: Understand work rate definition Work rate is the fraction of total work completed per day. 	ext{Work Rate} = \frac{	ext{Total Work}}{	ext{Total Days}} Step 2: Define total work as 1 complete job Since B completes the entire job, the total work equals 1. 	ext{Total Work} = 1 Step 3: Calculate B's daily work rate B completes the job in 15 days, so divide the work by the number of days. 	ext{B's Work Rate} = \frac{1}{15} 	ext{ per day} B's work rate is 1/15 of the job per day, which means B completes one-fifteenth of the job each day for 15 days to finish it completely.

Answer

A. 1/10

Answer

C. 1/20

Answer

D. 1/25

Question 3

If 5 workers can build a wall in 8 days, how many days will 10 workers take to build the same wall?

Accepted Answer

Correct answer: C. 4 days — This question tests the concept of inverse proportionality between the number of workers and the time required to complete a fixed task. Step 1: Calculate total work in worker-days Work is constant regardless of the number of workers, so we multiply workers by days. 	ext{Total Work} = 5 	ext{ workers} 	imes 8 	ext{ days} = 40 	ext{ worker-days} Step 2: Set up the equation with new number of workers With 10 workers, the same 40 worker-days of work must be completed. 10 	ext{ workers} 	imes d 	ext{ days} = 40 	ext{ worker-days} Step 3: Solve for the number of days Divide total work by the number of workers to find days required. d = \frac{40}{10} = 4 	ext{ days} When 10 workers work together, they will build the same wall in 4 days.

Answer

A. 2 days

Answer

B. 3 days

Answer

D. 5 days

Question 4

A can complete 60% of work in 9 days. How many days will A take to complete the entire work?

Accepted Answer

Correct answer: B. 15 days — 60% work is done in 9 days. Rate = 0.6/9 = 1/15 per day. Total days = 1/(1/15) = 15 days

Answer

A. 12 days

Answer

C. 18 days

Answer

D. 20 days

Question 5

Two pipes A and B can fill a tank in 10 hours and 15 hours respectively. If both pipes are opened together, in how many hours will the tank be filled?

Accepted Answer

Correct answer: B. 6 hours — When two pipes work together, their rates of filling add up. We use the concept of work rates: if a pipe fills a tank in t hours, its rate is \frac{1}{t} tanks per hour. **Step 1: Find the filling rate of each pipe** Pipe A fills the tank in 10 hours, so its rate is \frac{1}{10} tanks/hour. Pipe B fills the tank in 15 hours, so its rate is \frac{1}{15} tanks/hour. **Step 2: Find the combined filling rate** When both pipes work together, their rates add: 	ext{Combined rate} = \frac{1}{10} + \frac{1}{15} Find a common denominator (LCM of 10 and 15 is 30): \frac{1}{10} + \frac{1}{15} = \frac{3}{30} + \frac{2}{30} = \frac{5}{30} = \frac{1}{6} 	ext{ tanks/hour} **Step 3: Calculate time to fill one complete tank** If the combined rate is \frac{1}{6} tanks per hour, then the time to fill 1 complete tank is: 	ext{Time} = \frac{1 	ext{ tank}}{\frac{1}{6} 	ext{ tanks/hour}} = 1 	imes 6 = 6 	ext{ hours} **Answer: Both pipes together will fill the tank in 6 hours (Option B)**

Answer

A. 5 hours

Answer

C. 7.5 hours

Answer

D. 8 hours

Question 6

A train 240m long crosses a platform 360m long in 30 seconds. What is the speed of the train in km/h?

Accepted Answer

Correct answer: B. 72 km/h — Total distance = 240 + 360 = 600m. Time = 30 seconds. Speed = 600/30 = 20 m/s = 20 × 3.6 = 72 km/h

Answer

A. 70.2 km/h

Answer

C. 75.6 km/h

Answer

D. 80 km/h

Question 7

If the cost price of an article is ₹800 and it is sold at 25% profit, what is the selling price?

Accepted Answer

Correct answer: C. ₹1000 — Profit = 25% of 800 = 200. Selling Price = 800 + 200 = ₹1000

Answer

A. ₹900

Answer

B. ₹950

Answer

D. ₹1100

Question 8

A boat's speed in still water is 15 km/h and the speed of current is 3 km/h. If the boat travels 36 km upstream and returns, what is the total time taken?

Accepted Answer

Correct answer: B. 5 hours — Upstream speed = 15-3 = 12 km/h. Downstream speed = 15+3 = 18 km/h. Time upstream = 36/12 = 3 hours. Time downstream = 36/18 = 2 hours. Total = 5 hours

Answer

A. 4 hours

Answer

C. 5.5 hours

Answer

D. 6 hours

Quantitative Aptitude - MCQ Practice Questions