Quantitative Aptitude - Arithmetic Ability Questions

Q:

Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time (in seconds) which they take to cross each other, is:

A) 9 B) 9.6
C) 10 D) 10.8
 
Answer & Explanation Answer: D) 10.8

Explanation:

Relative speed = (60 + 40) km/hr =[ 100 x ( 5 / 18 ) ]m/sec = ( 250 /9 ) m/sec.
Distance covered in crossing each other = (140 + 160) m = 300 m.
Required time = [ 300 x ( 9/250 ) ] sec = ( 54/ 5 )sec = 10.8 sec.

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Filed Under: Problems on Trains

25 25106
Q:

Which of the following statement is correct about a triangle?

 

A) If the triangles are congruent then their area will be equal B) If the areas of two similar triangles are equal then the triangle is congruent
C) Two congruent triangles are always similar to each other D) All options are correct
 
Answer & Explanation Answer: D) All options are correct

Explanation:
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Filed Under: Area
Exam Prep: Bank Exams

0 25082
Q:

Variance of the data 2, 4, 5, 6, 8, 17 is 23.33. Then the variance of 4, 8, 10, 12, 16, 34 will be

 

A) 11.66 B) 46.66
C) 93.3333 D) 4.83
 
Answer & Explanation Answer: C) 93.3333

Explanation:
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Filed Under: Probability
Exam Prep: Bank Exams

5 25076
Q:

A train speeds past a pole in 15 seconds and a platform 100 m long in 25 seconds. Its length is:

A) 50 m B) 150 m
C) 200 m D) data inadequate
 
Answer & Explanation Answer: B) 150 m

Explanation:

Let the length of the train be x metres and its speed be y m/sec.
Then, (x/y)= 15   y =(x/15)

 

(x+100)/25 = x/15

 

=> 15(x + 100) = 25x

 

=> 15x + 1500 = 25x

 

=> 1500 = 10x

 

=> x = 150 m.

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Filed Under: Problems on Trains

39 25060
Q:

A sum of Rs. 12,500 amounts to Rs. 15,500 in 4 years at the rate of simple interest. What is the rate of interest

A) 3% B) 4%
C) 5% D) 6%
 
Answer & Explanation Answer: D) 6%

Explanation:

S.I. = Rs. (15500 - 12500) = Rs. 3000.

 

Rate = 100*300012500*4 % = 6%

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Filed Under: Simple Interest
Exam Prep: GRE

20 25051
Q:

In the 75 litres of mixture of milk and water, the ratio of milk and water is 4:1. The quantity of water required to make the ratio of milk and water 3:1 is 

A) 1 litre B) 3 litres
C) 4 litres D) 5 litres
 
Answer & Explanation Answer: D) 5 litres

Explanation:

Total quantity of mixture = 75 litre

Milk  :  Water  =  4  :  1   

            

                   3       :       1

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Filed Under: Alligation or Mixture

50 25043
Q:

Out of 17 applicants 8 boys and 9 girls. Two persons are to be selected for the job. Find the probability that at least one of the selected persons will be a girl.

A) 19/34 B) 5/4
C) 20/34 D) 25/34
 
Answer & Explanation Answer: D) 25/34

Explanation:

The events of selection of two person is redefined as first is a girl and second is a boy or first is boy and second is a girl or first is a girl and second is a girl.

So the required probability:
=817*916+917*816+817*716

 

934+934+734
2534

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Filed Under: Probability

21 25038
Q:

A and B can do a work in 4 hours and 12 hours respectively. A starts the work at 6 AM and they work alternately for one hour each. When will the work be completed?

A) 4 days B) 5 days
C) 6 days D) 7 days
 
Answer & Explanation Answer: C) 6 days

Explanation:

Work donee by A and B in the first two hours, working alternatively = First hour A + Second hour B = (1/4) + (1/12) = 1/3.

Thus, the total time required to complete the work  = 2 (3) = 6 days 

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Filed Under: Time and Work

45 24951