6500+ Quantitative Aptitude Questions and Answers With Explanation

Q:

A 270 metres long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. What is the length of the other train ?

A) 230 m	B) 240 m
C) 260 m	D) 320 m

Answer & Explanation Answer: A) 230 m

Explanation:

Relative speed = (120 + 80) km/hr

=(200*5/18)m/s = (500/9)m/s

Let the length of the other train be x metres.

Then, x+270/9 = 500/9

=> x + 270 = 500

=> x = 230.

Report Error

View Answer Report Error Discuss

Filed Under: Problems on Trains

19 17869

Q:

The ratio of the ages of Maala and Kala is 4 : 3. The total of their ages is 2.8 decades. The proportion of their ages after 0.8 decades will be [1 Decade = 10 years]

A) 4:3	B) 12:11
C) 7:4	D) 6:5

Answer & Explanation Answer: D) 6:5

Explanation:

Let, Maala’s age = 4A and Kala’s age = 3A
Then 4A + 3A = 28
A = 4
Maala’s age = 16 years
and Kala’s age = 12 years
Proportion of their ages after 8 is = (16 + 8) : (12 + 8)
= 24 : 20
= 6 : 5

Report Error

View Answer Report Error Discuss

Filed Under: Problems on Ages

41 17854

Q:

The ages of X and Y are in the proportion of 6:5 and total of their ages is 44 years. The proportion of their ages after 8 years will be

A) 3:6	B) 6:3
C) 8:7	D) 9:5

Answer & Explanation Answer: C) 8:7

Explanation:

Let current ages of X and Y correspondingly, is 6A & 5A
Given: 6A + 5A = 44
=> A = 4
Proportion of ages after 0.8 decades will be
6A + 8 : 5A + 8 $\Leftrightarrow$ 32:28 (or) 8:7

Report Error

View Answer Report Error Discuss

Filed Under: Problems on Ages

22 17848

Q:

An equilateral triangle is described on the diagonal of a square. What is the ratio of the area of the triangle to that of the square?

A) 1:2	B) 1:3
C) 2:3	D) 3^(1/2) :2

Answer & Explanation Answer: D) 3^(1/2) :2

Explanation:

area of a square = a² sq cm

length of the diagonal = $\sqrt{2 a}$ cm

area of equilateral triangle with side $\sqrt{2 a}$ = $\frac{\sqrt{3}}{4} * {(\sqrt{2 a})}^{2}$
required ratio = $\frac{\sqrt{3}}{4} * {(\sqrt{2 a})}^{2} : a^{2} = \sqrt{3} : 2$

Report Error

View Answer Report Error Discuss

Filed Under: Area
Exam Prep: Bank Exams
Job Role: Bank PO

14 17807

Q:

One type of liquid contains 25 % of benzene, the other contains 30% of benzene. A can is filled with 6 parts of the first liquid and 4 parts of the second liquid. Find the percentage of benzene in the new mixture.

A) 27 %	B) 26 %
C) 29 %	D) 21 %

Answer & Explanation Answer: A) 27 %

Explanation:

Let the percentage of benzene = X
(30 - X)/(X- 25) = 6/4 = 3/2
=> 5X = 135
X = 27

So, required percentage of benzene = 27 %

Report Error

View Answer Report Error Discuss

Filed Under: Alligation or Mixture
Exam Prep: AIEEE , Bank Exams , CAT , GATE , GRE
Job Role: Analyst , Bank Clerk , Bank PO , Network Engineer , Project Manager

30 17804

Q:

From a group of 7 men and 6 women, five persons are to be selected to form a committee so that at least 3 men are there on the committee. In how many ways can it be done?

A) 564	B) 735
C) 756	D) 657

Answer & Explanation Answer: C) 756

Explanation:

We may have (3 men and 2 women) or (4 men and 1 woman) or (5 men only).

Required number of ways= $(7 C_{3} * 6 C_{2}) + (7 C_{4} * 6 C_{1}) + 7 C_{5}$ = 756.

Report Error

View Answer Report Error Discuss

Filed Under: Permutations and Combinations

11 17793

Q:

A, B and C can complete a piece of work in 24,6 and 12 days respectively.Working together, they will complete the same work in:

A) 1/24 days	B) 7/24 days
C) 24/7 days	D) 4 days

Answer & Explanation Answer: C) 24/7 days

Explanation:

(A+B+C)'s 1 day's work = (1/24 + 1/6 + 1/12) = 7/24

so, A,B and C together will complete the work in 24/7 days.

Report Error

View Answer Report Error Discuss

Filed Under: Time and Work

32 17787

Q:

The ratio of speeds of a car, a train and a bus is 5:9:4. The average speed of the car, the bus and the train is 72 km/hr together. What is the average speed of the car and the train together ?

A) 84 km/hr	B) 96 km/hr
C) 72 km/hr	D) 60 km/hr

Answer & Explanation Answer: A) 84 km/hr

Explanation:

Let the speeds of the car, train and bus be 5x, 9x and 4x km/hr respectively.
Average speed = 5x + 9x + 4x/3 = 18x /3 = 6x km/hr.
Also, 6x = 72 => x = 12 km/hr
Therefore, the average speed of the car and train together is = $\frac{5 x + 9 x}{2}$ = 7x = 7 x 12 = 84 km/hr.

Report Error

View Answer Report Error Discuss

Filed Under: Average
Exam Prep: GRE , GATE , CAT , Bank Exams , AIEEE
Job Role: Bank PO , Bank Clerk

20 17781

Quantitative Aptitude - Arithmetic Ability Questions

Quick Links