6500+ Quantitative Aptitude Questions and Answers With Explanation

Q:

The average of any 5 consecutive odd natural numbers is k . If two more such numbers , just next to the previous 5 numbers are added , the new average becomes

A) 2(k+1)	B) 2k-3
C) 2k+1	D) k+2

Answer & Explanation Answer: D) k+2

Explanation:

The 5 consecutive odd numbers whose average is k are (k-4), (k-2), k, (k+2), (k+4)

Again the average of (k-4), (k-2), k, (k+2), (k+4), (k+6), (k+8) is (k+2)

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Filed Under: Average

14 16368

Q:

Two trains having equal lengths, take 10 seconds and 15 seconds respectively to cross a post. If the length of each train is 120 meters, in what time (in seconds) will they cross each other when traveling in opposite direction?

A) 10	B) 25
C) 12	D) 20

Answer & Explanation Answer: C) 12

Explanation:

Speed of train 1 = $(\frac{120}{10}) m / s e c$ = 12 m/sec

Speed of train 2 = $(\frac{120}{15}) m / s e c$ = 8 m/sec

if they travel in opposite direction, relative speed = 12 + 8 = 20 m/sec

distance covered = 120 + 120 = 240 m

time = distance/speed = 240/20 = 12 sec

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Filed Under: Problems on Trains

22 16367

Q:

The third proportional to $(x^{2} - y^{2})$ and $(x - y)$ is :

A) (x + y )	B) (x - y)
C) (x + y) / ( x - y)	D) (x -y) / ( x + y)

Answer & Explanation Answer: D) (x -y) / ( x + y)

Explanation:

Let the third proportional to $(x^{2} - y^{2})$ and $(x - y)$ be z. Then,

$(x^{2} - y^{2}) : (x - y) : : (x - y) : z$

$= > (x^{2} - y^{2}) * z = {(x - y)}^{2}$

=> z= $\frac{{(x - y)}^{2}}{(x^{2} - y^{2})} = \frac{(x - y)}{(x + y)}$

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Filed Under: Ratios and Proportions

65 16367

Q:

Five men and nine women can do a piece of work in 10 days. Six men and twelve women can do the same work in 8 days. In how many days can three men and three women do the work ?

A) 18 days	B) 20 days
C) 16 days	D) 14 days

Answer & Explanation Answer: B) 20 days

Explanation:

(5m + 9w)10 = (6m + 12w)8

=> 50m + 90w = 48w + 96 w => 1m = 3w

5m + 9w = 5m + 3m = 8m

8 men can do the work in 10 days.

3m +3w = 3m + 1w = 4m

So, 4 men can do the work in (10 x 8)/4 = 20 days.

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Filed Under: Time and Work
Exam Prep: GATE , CAT , Bank Exams , AIEEE
Job Role: Bank PO , Bank Clerk

9 16333

Q:

How many arrangements can be made out of the letters of the word DRAUGHT, the vowels never beings separated?

A) 1440	B) 720
C) 360	D) 640

Answer & Explanation Answer: A) 1440

Explanation:

There are 7 letters in the word DRAUGHT, the two vowels are A and U. Since, the vowels are not to be separated, AU can be considered as one entity. Therefore, the number of letters will be 6 instead of 7. The permutations will be P(6,6) = 6! ways.

But the two vowels A and U can be arranged in two ways, i.e. AU and UA. The required number of arrangements = 2!.6! = 1440 ways.

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Filed Under: Permutations and Combinations

15 16330

Q:

A and B entered into a partnership investing Rs. 13,000 and Rs. 12,000 respectively.After 3 months, A withdrew Rs. 5000 while B invested Rs. 5000 more, After 3 more months, C joins the business with a capital of Rs. 21,000, The share of B exceeds that of C, out of a total profit of Rs. 26,400 after one year by

A) 3500	B) 3600
C) 3700	D) 3800

Answer & Explanation Answer: B) 3600

Explanation:

A : B : C = (16000 * 3 + 11000 * 9) : (12000 * 3 + 17000 * 9) : (21000 * 6)

= 147 : 189 : 126

= 7 : 9 ; 6.

Difference of B and C's shares = Rs. ( 26400 * 9/22 - 26400 * 6/22 ) = Rs. 3600.

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Filed Under: Partnership

13 16325

Q:

Two trains of equal length, running with the speeds of 60 and 40 kmph, take 50 seconds to cross each other while they are running in the same direction. What time will they take to cross each other if they are running in opposite directions ?

A) 10 sec	B) 11 sec
C) 12 sec	D) 8 sec

Answer & Explanation Answer: A) 10 sec

Explanation:

Relative Speed = 60 -40 = 20 x 5/18 = 100/18

Time = 50

Distance = 50 x 100/18 = 2500/9

Relative Speed = 60 + 40 = 100 x 5/18

Time = 2500/9 x 18/500 = 10 sec.

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Filed Under: Problems on Trains
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

13 16296

Q:

The median of the data 1, 1/2, 1/2, 3/4, 1/4, 2, 1/2, 1/4, 3/4 is

A) 1/4	B) 1/2
C) 1/6	D) 3/4

Quantitative Aptitude - Arithmetic Ability Questions

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