MCQ Guru LogoMCQ Guru
AI-assisted, automatically checked• Updated August 2026

Quantitative Aptitude MCQs

Aptitude MCQs on percentages, profit & loss, ratios, time & work, and speed & distance.

48 MCQsAptitudeAll Levels
Key Concept Overview & Exam Context

Review core principles of Quantitative Aptitude before answering questions. These questions simulate placement technical assessments (TCS, Infosys, Amazon), university exams (CS/IT), and technical certifications.

Target Readiness
Placements & Job Interviews
Question Format
Multiple-Choice with Explanations
Explained Solutions
Written explanations

Quantitative Aptitude MCQ Questions

Page 1 of 1 (48 total)
Q1

A sum of money doubles itself in 8 years at simple interest. In how many years will it triple?

medium
View Answer & Explanation
Correct Answer: 16 years
Explanation:
If the sum doubles in 8 years, the interest earned equals the original principal in that time, meaning the rate generates one full principal amount every 8 years, so tripling requires two such intervals, or 16 years.
Q2

What is the compound interest on 10,000 for 2 years at 10% per annum, compounded annually?

medium
View Answer & Explanation
Correct Answer: 2,100
Explanation:
After the first year the amount grows to 11,000, and after the second year it grows to 12,100, meaning the total compound interest earned over both years is 2,100.
Q3

If the ratio of two numbers is 3:5 and their sum is 64, what is the larger number?

easy
View Answer & Explanation
Correct Answer: 40
Explanation:
Splitting 64 into 8 equal parts based on the ratio 3 plus 5 gives 8 parts of 8 each, so the larger number, which represents 5 parts, equals 5 times 8, or 40.
Q4

A train 150 meters long crosses a pole in 15 seconds. What is the speed of the train in km/h?

medium
View Answer & Explanation
Correct Answer: 36 km/h
Explanation:
The train's speed in meters per second is 150 divided by 15, which equals 10 m/s, and converting to km/h by multiplying by 3.6 gives 36 km/h.
Q5

What is the average of the first 10 natural numbers?

easy
View Answer & Explanation
Correct Answer: 5.5
Explanation:
The sum of the first 10 natural numbers is 55, and dividing that sum by 10 gives an average of 5.5.
Q6

A shopkeeper marks an item at 25% above cost price and gives a discount of 10% on the marked price. What is his overall profit percentage?

hard
View Answer & Explanation
Correct Answer: 12.5%
Explanation:
If the cost price is 100, the marked price becomes 125, and a 10% discount on that gives a selling price of 112.5, which represents a profit of 12.5 over the original cost price of 100.
Q7

What is the least common multiple (LCM) of 12 and 18?

easy
View Answer & Explanation
Correct Answer: 36
Explanation:
Breaking both numbers into prime factors gives 12 as 2 squared times 3, and 18 as 2 times 3 squared, and taking the highest power of each prime factor gives an LCM of 36.
Q8

If 5 workers can complete a task in 12 days, how many days will 10 workers take to complete the same task, assuming equal work rate?

easy
View Answer & Explanation
Correct Answer: 6 days
Explanation:
The total work can be measured as 5 workers times 12 days, which equals 60 worker-days, and dividing that total by 10 workers gives 6 days.
Q9

What is the probability of getting at least one head when a fair coin is tossed twice?

medium
View Answer & Explanation
Correct Answer: 3/4
Explanation:
There are four equally likely outcomes when tossing a coin twice, and only one of them, tails followed by tails, has no heads at all, so the probability of at least one head is 3 out of 4.
Q10

A car travels 60 km at 30 km/h and then another 60 km at 60 km/h. What is its average speed for the entire journey?

hard
View Answer & Explanation
Correct Answer: 40 km/h
Explanation:
The total distance is 120 km, and the total time taken is 2 hours for the first leg plus 1 hour for the second leg, or 3 hours total, giving an average speed of 120 divided by 3, which is 40 km/h.
Q11

In how many ways can the letters of the word 'BOOK' be arranged?

hard
View Answer & Explanation
Correct Answer: 12
Explanation:
The word BOOK has 4 letters where the letter O repeats twice, so the total arrangements are 4 factorial divided by 2 factorial to account for the repetition, which equals 12.
Q12

What is the value of the highest common factor (HCF) of 24 and 36?

easy
View Answer & Explanation
Correct Answer: 12
Explanation:
The prime factorization of 24 is 2 cubed times 3, and 36 is 2 squared times 3 squared, so taking the lowest power of each common prime factor gives an HCF of 12.
Q13

A man's age is 4 times his son's age. After 5 years, his age will be 3 times his son's age. What is the son's current age?

hard
View Answer & Explanation
Correct Answer: 10 years
Explanation:
Letting the son's current age be x makes the father's age 4x, and after 5 years the equation 4x plus 5 equals 3 times x plus 5 solves to x equals 10, the son's current age.
Q14

If a boat travels 20 km downstream in 2 hours and the same distance upstream in 4 hours, what is the speed of the boat in still water?

hard
View Answer & Explanation
Correct Answer: 7.5 km/h
Explanation:
Downstream speed works out to 10 km/h and upstream speed works out to 5 km/h, and since downstream speed equals boat speed plus current while upstream speed equals boat speed minus current, averaging the two gives a still water speed of 7.5 km/h.
Q15

What percentage of 250 is 75?

easy
View Answer & Explanation
Correct Answer: 30%
Explanation:
Dividing 75 by 250 gives 0.3, and multiplying by 100 converts that to a percentage, which is 30%.
Q16

A mixture contains milk and water in the ratio 4:1. If 5 liters of water is added, the ratio becomes 2:1. What was the original quantity of milk?

hard
View Answer & Explanation
Correct Answer: 20 liters
Explanation:
Letting the original milk and water be 4x and x respectively, adding 5 liters of water changes the ratio to 4x to x plus 5 equals 2 to 1, which solves to x equals 5, making the original milk quantity 4 times 5, or 20 liters.
Q17

What is the next number in the sequence: 2, 6, 12, 20, 30, ___?

medium
View Answer & Explanation
Correct Answer: 42
Explanation:
The differences between consecutive terms are 4, 6, 8, and 10, increasing by 2 each time, so the next difference should be 12, making the next term 30 plus 12, which is 42.
Q18

If the simple interest on a sum for 3 years at 8% per annum is 1,200, what is the principal amount?

medium
View Answer & Explanation
Correct Answer: 5,000
Explanation:
Using the simple interest formula, principal equals interest divided by rate times time, so 1,200 divided by 0.08 times 3 equals 5,000.
Q19

Two numbers are in the ratio 2:3. If their LCM is 48, what is the smaller number?

hard
View Answer & Explanation
Correct Answer: 16
Explanation:
When two numbers share the ratio 2 to 3 with no other common factors, their LCM equals 2 times 3 times a common multiplier, so 6 times the multiplier equals 48, giving a multiplier of 8, and the smaller number of 2 times 8 equals 16.
Q20

A can do a piece of work in 20 days and B can do it in 30 days. They work together for 4 days and then A leaves. How many more days will B need to finish the remaining work?

hard
View Answer & Explanation
Correct Answer: 20 days
Explanation:
Working together for 4 days completes 4 times their combined daily rate of 1/20 plus 1/30, which is 4 times 1/12, or 1/3 of the work, leaving 2/3 of the work for B alone. Since B's rate is 1/30 per day, finishing the remaining 2/3 takes B 20 days.
Q21

A sum of money at simple interest amounts to 720 in 2 years and to 810 in 5 years. What is the principal amount?

hard
View Answer & Explanation
Correct Answer: 600
Explanation:
The interest for the extra 3 years is 90, so the yearly interest is 30. Over 2 years that is 60 interest, so the principal is 720 minus 60, which equals 600.
Q22

If the ratio of ages of A and B is 4:5 and the sum of their ages is 54 years, what is A's age?

easy
View Answer & Explanation
Correct Answer: 24 years
Explanation:
The total of 4 plus 5 parts is 9 parts representing 54 years, so each part equals 6 years. A's age, being 4 parts, works out to 24 years.
Q23

A train 200 meters long is running at 72 km/h. How long will it take to cross a platform 300 meters long?

medium
View Answer & Explanation
Correct Answer: 25 seconds
Explanation:
The train must cover its own length plus the platform, a total of 500 meters. At 72 km/h, which is 20 meters per second, this takes 500 divided by 20, or 25 seconds.
Q24

What is the average of the first 15 odd natural numbers?

easy
View Answer & Explanation
Correct Answer: 15
Explanation:
The first 15 odd numbers form an arithmetic sequence starting at 1 with a common difference of 2, and the average of such a sequence equals the middle term, which is 15.
Q25

A shopkeeper sells an article at a loss of 15%. If he had sold it for 90 more, he would have made a profit of 10%. What is the cost price of the article?

hard
View Answer & Explanation
Correct Answer: 360
Explanation:
The difference between a 10% profit and a 15% loss is 25% of the cost price, and this gap equals 90. So the cost price is 90 divided by 0.25, which is 360.
Q26

What is the least common multiple (LCM) of 15, 20, and 30?

medium
View Answer & Explanation
Correct Answer: 60
Explanation:
Breaking each number into prime factors gives 15 as 3 times 5, 20 as 2 squared times 5, and 30 as 2 times 3 times 5. Taking the highest powers of each prime gives an LCM of 60.
Q27

If 8 men can build a wall in 15 days, how many days will 12 men take to build the same wall, assuming equal work rate?

medium
View Answer & Explanation
Correct Answer: 10 days
Explanation:
The total work is constant, equal to 8 times 15, or 120 man-days. Dividing that by 12 men gives 10 days needed to finish the same wall.
Q28

A bag contains 4 red balls and 6 blue balls. What is the probability of drawing a red ball at random?

easy
View Answer & Explanation
Correct Answer: 2/5
Explanation:
There are 4 red balls out of a total of 10 balls in the bag, so the probability of drawing a red ball is 4 out of 10, which simplifies to 2 over 5.
Q29

A car covers a certain distance at 40 km/h and returns the same distance at 60 km/h. What is the average speed for the entire round trip?

medium
View Answer & Explanation
Correct Answer: 48 km/h
Explanation:
For two equal distances covered at different speeds, the average speed is the harmonic mean, calculated as 2 times 40 times 60 divided by the sum of 40 and 60, which gives 48 km/h.
Q30

In how many ways can the letters of the word 'LEVEL' be arranged?

hard
View Answer & Explanation
Correct Answer: 30
Explanation:
LEVEL has 5 letters where L appears twice and E appears twice. The total arrangements are 5 factorial divided by 2 factorial times 2 factorial, which equals 30.
Q31

What is the highest common factor (HCF) of 48 and 60?

easy
View Answer & Explanation
Correct Answer: 12
Explanation:
The prime factors of 48 are 2 to the fourth power times 3, and of 60 are 2 squared times 3 times 5. Taking the lowest common powers gives an HCF of 12.
Q32

A father is currently three times as old as his son. In 12 years, he will be twice as old as his son. What is the son's current age?

hard
View Answer & Explanation
Correct Answer: 12 years
Explanation:
Letting the son's age be x, the father's age is 3x. In 12 years, 3x plus 12 equals twice of x plus 12, which simplifies to x equals 12, the son's current age.
Q33

A boat travels 30 km downstream in 3 hours and returns upstream in 5 hours. What is the speed of the stream?

medium
View Answer & Explanation
Correct Answer: 2 km/h
Explanation:
Downstream speed is 10 km/h and upstream speed is 6 km/h. Since the stream speed is half the difference between these two, it works out to 2 km/h.
Q34

What percentage of 320 is 80?

easy
View Answer & Explanation
Correct Answer: 25%
Explanation:
Dividing 80 by 320 gives 0.25, and multiplying by 100 converts that into a percentage, giving 25 percent.
Q35

A mixture of 60 liters contains milk and water in the ratio 2:1. How much water should be added to make the ratio 1:1?

medium
View Answer & Explanation
Correct Answer: 20 liters
Explanation:
The mixture initially has 40 liters of milk and 20 liters of water. To make the ratio equal, water needs to equal milk at 40 liters, meaning 20 more liters must be added.
Q36

What is the next number in the sequence: 1, 4, 9, 16, 25, ___?

easy
View Answer & Explanation
Correct Answer: 36
Explanation:
The sequence lists perfect squares in order: 1 squared, 2 squared, 3 squared, and so on. The next term, 6 squared, equals 36.
Q37

If the simple interest on a sum for 4 years at 6% per annum is 960, what is the principal amount?

medium
View Answer & Explanation
Correct Answer: 4000
Explanation:
Using the simple interest formula, the principal equals the interest divided by the rate times time, so 960 divided by the product of 0.06 and 4 gives 4000.
Q38

Two numbers are in the ratio 5:7. If their HCF is 6, what are the two numbers?

medium
View Answer & Explanation
Correct Answer: 30 and 42
Explanation:
Since the ratio is in its simplest form, the HCF multiplies each part of the ratio directly, giving 5 times 6 equals 30 and 7 times 6 equals 42.
Q39

A can complete a piece of work in 12 days and B can complete it in 18 days. They work together for 4 days and then A leaves. How many more days will B need to finish the remaining work?

hard
View Answer & Explanation
Correct Answer: 6 days
Explanation:
Working together for 4 days completes 4 times the combined rate of 1/12 plus 1/18, which is 5/9 of the work. The remaining 4/9 of the work is finished by B alone in 4/9 divided by 1/18, which is 8 days.
Q40

If the price of sugar increases by 25%, by what percentage should a household reduce its consumption to keep expenditure unchanged?

hard
View Answer & Explanation
Correct Answer: 20%
Explanation:
To keep expenditure the same after a 25% price increase, consumption must be reduced by 25 divided by 125, expressed as a percentage, which comes out to 20%.
Q41

What is the compound interest on 8,000 for 2 years at 5% per annum, compounded annually?

medium
View Answer & Explanation
Correct Answer: 820
Explanation:
After the first year the amount grows to 8,400, and after the second year it grows to 8,820. Subtracting the original principal of 8,000 gives a compound interest of 820.
Q42

A sum of money becomes 4 times itself in 15 years at simple interest. What is the annual rate of interest?

hard
View Answer & Explanation
Correct Answer: 20%
Explanation:
If the sum becomes 4 times itself, the interest earned equals 3 times the principal over 15 years. Using the simple interest formula, the rate works out to 20% per annum.
Q43

A dice is rolled once. What is the probability of getting a number greater than 4?

easy
View Answer & Explanation
Correct Answer: 1/3
Explanation:
Numbers greater than 4 on a standard six sided die are 5 and 6, giving 2 favorable outcomes out of 6 total, which simplifies to 1 over 3.
Q44

A train covers a distance of 450 km at a certain speed. If the speed had been 15 km/h more, it would have taken 1 hour less. What is the original speed of the train?

hard
View Answer & Explanation
Correct Answer: 75 km/h
Explanation:
Setting up the relationship between distance, speed, and time and solving the resulting equation shows that the original speed of the train is 75 km/h.
Q45

If x:y = 3:4 and y:z = 2:5, what is x:y:z?

medium
View Answer & Explanation
Correct Answer: 3:4:10
Explanation:
To combine the ratios, y needs to match in both, so scaling x:y to 3:4 and y:z to 4:10 keeps y consistent, giving the combined ratio x:y:z as 3:4:10.
Q46

If the price of an item is increased by 20% and then decreased by 20%, what is the net percentage change in price?

medium
View Answer & Explanation
Correct Answer: 4% decrease
Explanation:
Net change = +20 - 20 - (20*20)/100 = -4%. The net price decreases by 4%.
Q47

If the price of an item is increased by 20% and then decreased by 20%, what is the net percentage change in price?

medium
View Answer & Explanation
Correct Answer: 4% decrease
Explanation:
Net change = +20 - 20 - (20*20)/100 = -4%. The net price decreases by 4%.
Q48

A can complete a piece of work in 10 days and B can complete the same work in 15 days. How many days will they take working together?

easy
View Answer & Explanation
Correct Answer: 6 days
Explanation:
1/10 + 1/15 = (3 + 2)/30 = 5/30 = 1/6. Together they will take 6 days.