Quantitative Aptitude - Arithmetic Ability Questions

Q:

Two numbers are in the ratio 3 : 7. If 6 be added to each of them, then they are in the ratio 5 : 9. Find the numbers ?

A) 11 & 17 B) 7 & 17
C) 9 & 21 D) 13 & 23
 
Answer & Explanation Answer: C) 9 & 21

Explanation:

Let the two numbers be x and y

Given x : y = 3 : 7 .....(1)

Now, x+6 : y+6 = 5 : 9 .....(2)

From (1), x = 3y/7

From (2), 5y - 9x = 24

=> 5y - 9(3y/7) = 24

=> y = 21

=> From(1), x = 9

Hence, the two numbers be 9 and 21

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

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Q:

Arjun and Bhishma are running on a circular track of length 600m. Speed of Arjun is 30 m/s and that of Bhishma is 20 m/s .They start fro the same point at the same time in the same direction. When will they meet again for the first time?

Answer

SolTime = Circumference Relative Speed = 60010 = 60 sec.


 


Actually Arjun has to make a lead of 600 m, because when Arjun will be 600m ahead of Bhishma, they will be together again as a person when completes the total length it starts retracing he same path and thus Arjun and Bhishma can be together again.


 


Since , they make  a difference of 10 m in 1 second. so, he will create 600m difference in 60 second.

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Subject: Time and Distance Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Bank Clerk , Bank PO

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Q:

The height of the wall is 6 times its width and lenght of the wall is 7 times its height .if the volume of the wall be 16128 cu.m.its width is

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

Explanation:

Let width = x

Then, height = 6x and length = 42x 

42x * 6x * x = 16128

x = 4

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Filed Under: Volume and Surface Area
Exam Prep: Bank Exams
Job Role: Bank PO

12 11453
Q:

The angle between the minute hand and the hour hand of a clock when the time is 4.20, is:

A) 0 B) 10
C) 30 D) 60
 
Answer & Explanation Answer: B) 10

Explanation:

Angle traced by hour hand in 133hrs = 36012×13301300 

Angle traced by min. hand in 20 min = 36060×200 =1200 

Required angle = (130 - 120)º = 10º

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

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Q:

The present worth of a sum due sometime hence is Rs. 576 and the banker's gain is Rs.

16. The true discount is:

A) 78 B) 96
C) 105 D) 85
 
Answer & Explanation Answer: B) 96

Explanation:

T.D. = P.W. x B.G. = 576 x 16 = 96.

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Filed Under: Banker's Discount

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Q:

Amy has to visit towns B and C in any order. The roads connecting these towns with her home are shown on the diagram. How many different routes can she take starting from A and returning to A, going through both B and C (but not more than once through each) and not travelling any road twice on the same trip?

A) 10 B) 8
C) 6 D) 4
 
Answer & Explanation Answer: B) 8

Explanation:

Amy can travel clockwise or anticlockwise on the diagram.

Clockwise, she has no choice of route from A to B, a choice of one out of two routes from B to C, and a choice of one out of two routes from C back to A. This gives four possible routes.

Similarly, anticlockwise she has four different routes.

Total routes = 8

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Filed Under: Time and Distance
Exam Prep: GRE

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Q:

Ashwin fires two bullets from the same place at an interval of 15 minutes but Rahul sitting in a bus approaching the place hears the second sound 14 minutes 30 seconds after the first. If sound travels at the speed of 330 meter per second, what is the approximate speed of bus?

A) 330/29 m/s B) 330 x 30 m/s
C) 330/14 m/s D) 330/900 m/s
 
Answer & Explanation Answer: A) 330/29 m/s

Explanation:

Second gun shot take 30 sec to reach rahul imples distance between two.

given speed of sound = 330 m/s

Now, distance = 330 m/s x 30 sec 

 

Hence, speed of the bus = d/t = 330x30/(14x60 + 30) = 330/29 m/s.

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Q:

A perfect cube is an integer whose cube root is an integer. For example, 27, 64 and 125 are perfect cubes. If p and q are perfect cubes, which of the following will not necessarily be a perfect cube?

A) 8p B) pq
C) pq+27 D) -p
 
Answer & Explanation Answer: C) pq+27

Explanation:

A perfect cube will have prime factors that are in groups of 3; for example 125 has the prime factors 5 x 5 x 5 , and 64 x 125 will also be a cube because its factors will be 4 x 4 x 4 x 5 x 5 x 5

Consider the answer choices in turn.

8 is the cube of 2, and p is a cube, and so the product will also be a cube.

pq will also be a cube as shown above.

pq is a cube and so is 27, but their sum need not be a cube. Consider the case where p =1 and q = 8, the sum of pq and 27 will be 35 which has factors 5 x 7 and is not a cube.

-p will be a cube.

Since the difference between p and q is raised to the power of 6, this expression will be a cube (with cube root = difference squared).

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Filed Under: Numbers

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