Quantitative Aptitude - Arithmetic Ability Questions

Q:

A box contains 5 detective and 15 non-detective bulbs. Two bulbs are chosen at random. Find the probability that both the bulbs are non-defective.

A) 5/19 B) 3/20
C) 21/38 D) None of these
 
Answer & Explanation Answer: C) 21/38

Explanation:

n(S) = C220 = 190 

n(E) = C215 = 105 

Therefore, P(E) = 105/190 = 21/38

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Filed Under: Probability

12 15778
Q:

Find the total numbers greater than 4000 that can be formed with digits 2, 3, 4, 5, 6 no digit being repeated in any number ?

A) 120 B) 256
C) 192 D) 244
 
Answer & Explanation Answer: C) 192

Explanation:

We are having with digits 2, 3, 4, 5 & 6 and numbers greater than 4000 are to be formed, no digit is repeated.

 

The number can be 4 digited but greater than 4000 or 5 digited.

 

Number of 4 digited numbers greater than 4000 are
4 or 5 or 6 can occupy thousand place => 3 x P34 = 3 x 24 = 72. 

 

5 digited numbers = P55 = 5! = 120 

So the total numbers greater than 4000 = 72 + 120 = 192

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

21 15771
Q:

The perimeter of a square is equal to twice the perimeter of a rectangle of length 8cm and breadth 7cm. What is the circumference of a semicircle whose diameter is equal to the side of the square ?

A) 55.12 cm B) 22.54 cm
C) 42.51 cm D) 38.57 cm
 
Answer & Explanation Answer: D) 38.57 cm

Explanation:

We know that perimeter of rectangle = 2(l+b) = 2(8+7)= 30cm
Given perimeter of square is twice the perimeter of rectangle = 2(30) = 60cm
Therefore, side of the square is = 1/4 x 60 = 15cm
Circumference of the required semicircle = πr + 2r = 227× 152 + 2×152 = 23.57 + 15 = 38.57cm.

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

6 15755
Q:

A man invested Rs. 4455 in Rs. 10 shares quoted at Rs. 8.25. If the rate of dividend be 12%, his annual income is:

A) 107.04 B) 648
C) 500 D) 648.60
 
Answer & Explanation Answer: B) 648

Explanation:

Number of shares = 44558.25= 540.

 

Face value = Rs. (540 x 10) = Rs. 5400.

 

Annual income = Rs.12100*5400 = Rs. 648.

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Filed Under: Stocks and Shares

6 15747
Q:

Two trains of equal length , running in opposite directions , pass a pole in 18 and 12 seconds. The trains will cross each other in 

A) 14.4 sec B) 15.5 sec
C) 18.8 sec D) 20.2 sec
 
Answer & Explanation Answer: A) 14.4 sec

Explanation:

Let the length of the train be L metres

 

Speed of first train = 360018xL m/hour

 

Speed of secxond train = 360012xL m/hour

 

When running in opposite directions, relative speed = 200 L + 300 L m/hour

 

Distance to be covered = L + L = 2L metre

 

Time taken = 2L500Lx3600 sec

 

                 =14.4 sec

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Filed Under: Problems on Trains
Exam Prep: AIEEE , Bank Exams , CAT
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25 15747
Q:

5/9 of the part of the population in a village are females. If 30 % of the females are married. The percentage of unmarried males in the total males is ?

A) 62.5 % B) 125 %
C) 84.32 % D) 46.87 %
 
Answer & Explanation Answer: A) 62.5 %

Explanation:

Let total population = p
number of females = 5p/9
number of males =(p-5p/9) = 4p/9
married females = 30% of 5p/9 = 30x5p/100x9 = p/6
married males = p/6
unmarried males =(4p/9-p/6) = 5p/18
Percentage of unmarried males in the total males = {(5p/18)/4p/9}x100 = (5p/18)x(9/4p) = 125/2 % = 62.5%

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Filed Under: Percentage
Exam Prep: AIEEE , Bank Exams , CAT , GATE
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21 15729
Q:

Sachin is younger than Rahul by 7 years. If the ratio of their ages is 7:9, find the age of Sachin

A) 24.5 B) 25.5
C) 26.5 D) 27.5
 
Answer & Explanation Answer: A) 24.5

Explanation:

If Rahul age is x, then Sachin age is x - 7,

 

so, (x-7)/x =7/9

 

 9x - 63 = 7x
 2x = 63
 x = 31.5

So Sachin age is 31.5 - 7 = 24.5

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Filed Under: Problems on Ages

60 15724
Q:

A man in a train notices that he can count 41 telephone posts in one minute. If they are known to be 50 metres apart, then at what speed is the train travelling?

A) 60 km/hr B) 100 km/hr
C) 110 km/hr D) 120 km/hr
 
Answer & Explanation Answer: D) 120 km/hr

Explanation:

Number of gaps between 41 poles = 40
So total distance between 41 poles = 40*50
= 2000 meter = 2 km
In 1 minute train is moving 2 km/minute.
Speed in hour = 2*60 = 120 km/hour

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Filed Under: Time and Distance
Exam Prep: GRE

25 15705