Quantitative Aptitude - Arithmetic Ability Questions

Q:

In a charity show tickets numbered consecutively from 101 through 350 are placed in a box. What is the probability that a ticket selected at random (blindly) will have a number with a hundredth digit of 2?

A) 0.25 B) 0.5
C) 0.75 D) 0.40
 
Answer & Explanation Answer: D) 0.40

Explanation:

250 numbers between 101 and 350 i.e. n(S)=250

n(E)=100th digits of 2 = 299−199 = 100

P(E)= n(E)/n(S) = 100/250 = 0.40

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Filed Under: Probability

3 9566
Q:

A loan shark made a loan of $100 to be repaid with $120 at the end of one month. What was the annual interest rate?

A) 210% B) 220%
C) 230% D) 240%
 
Answer & Explanation Answer: D) 240%

Explanation:

r=I/PT

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Filed Under: Simple Interest
Exam Prep: Bank Exams
Job Role: Bank PO

5 9563
Q:

1747 + 13212 - ? = 1123

A) 16 B) 17
C) 18 D) 19
 
Answer & Explanation Answer: D) 19

Explanation:

1747 + 13212 - ? = 1123

1237 + 15812 - ? = 353

=> ? = 1237 + 15812 - 353

=> ? = 1476 + 1106 - 98084

=> ? = 19.07

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Filed Under: Simplification
Exam Prep: AIEEE , Bank Exams , CAT
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13 9554
Q:

A is two years older than B who is twice as old as C. If the total of the ages of A, B and C be 27, then how old is B ?

A) 10 yrs B) 11 yrs
C) 12 yrs D) 13 yrs
 
Answer & Explanation Answer: A) 10 yrs

Explanation:

Let C's age be x years.
Then, B's age = 2x years.
A's age = (2x + 2) years.
(2x + 2) + 2x + x = 27
5x = 25 => x = 5
Hence, B's age = 2x = 10 years.

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Filed Under: Problems on Ages
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4 9548
Q:

The probability of occurance of two two events A and B are 1/4 and 1/2 respectively. The probability of their simultaneous occurrance is 7/50. Find the probability that neither A nor B occurs.

A) 25/99 B) 39/100
C) 61/100 D) 17/100
 
Answer & Explanation Answer: B) 39/100

Explanation:

P ( neither A nor B) = PA and B  

 

=  PAB=  PAB1-PAB  

 

1-61100=39100

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Filed Under: Probability

8 9540
Q:

Train X crosses a stationary train Y in 60 seconds and a pole in 25 seconds with the same speed. The length of the train X is 300 m. What is the length of the stationary train Y ?

A) 360 m B) 420 m
C) 460 m D) 320 m
 
Answer & Explanation Answer: B) 420 m

Explanation:

Let the length of the stationary train Y be LY
Given that length of train X, LX = 300 m
Let the speed of Train X be V.
Since the train X crosses train Y and a pole in 60 seconds and 25 seconds respectively.
=> 300/V = 25 ---> ( 1 )
(300 + LY) / V = 60 ---> ( 2 )
From (1) V = 300/25 = 12 m/sec.
From (2) (300 + LY)/12 = 60
=> 300 + LY = 60 (12) = 720
=> LY = 720 - 300 = 420 m
Length of the stationary train = 420 m

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Filed Under: Problems on Trains
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7 9536
Q:

88 cubic centimetres of silver is drawn into a wire 1 mm in diameter. The length of the wire in metres will be ?

A) 112 mts B) 84 mts
C) 96 mts D) 108 mts
 
Answer & Explanation Answer: B) 84 mts

Explanation:

Vol of silver = πR2h  = 66 C.C  

Given D= 1mm => R = D/2 = 1/20 cm  

 

=> 227×1202×h = 66

= 66 x 400 x (7/22) = 8400 cm = 84 mtrs.

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Filed Under: Volume and Surface Area
Exam Prep: CAT , Bank Exams , AIEEE
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11 9526
Q:

5 men and 3 boys can together cultivate a 23 acre field in 4 days and 3 men and 2 boys together can cultivate a 7 acre field in 2 days. How many boys will be needed together with 7 men, if they cultivate 45 acre of field in 6 days.

A) 6 B) 4
C) 2 D) 3
 
Answer & Explanation Answer: C) 2

Explanation:

Let work done by 1 man in i day be m

and Let work done by 1 boy in 1 day be b

From the given data,

4(5m + 3b) = 23

20m + 12b = 23....(1)

2(3m + 2b) = 7

6m + 4b = 7 ....(2)

By solving (1) & (2), we get

m = 1, b = 1/4

Let the number of required boys = n

6(7 1 + n x 1/4) = 45

=> n = 2.

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