Quantitative Aptitude - Arithmetic Ability Questions

Q:

if the price of a book is first decreased by 25% and then increased by 20%, then the net change in the price will be  : 

A) 10 B) 20
C) 30 D) 40
 
Answer & Explanation Answer: A) 10

Explanation:

Let the original price be Rs. 100.

New final price  = 120 %  of (75 % of Rs. 100) = Rs. [(120/100) * (75/100) * 100] = Rs. 90.

Decrease = 10%

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Filed Under: Percentage

511 97480
Q:

The compound interest on rs.30000 at 7% per annum is Rs.4347. The period is

A) 2 years B) 2.5 years
C) 3 years D) 4 years
 
Answer & Explanation Answer: A) 2 years

Explanation:

Amount = Rs.(30000+4347) = Rs.34347

 

let the time be n years

 

Then,30000(1+7/100)^n = 34347

 

(107/100)^n = 34347/30000 = 11449/10000 = (107/100)^2

 

n = 2years

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Filed Under: Compound Interest
Exam Prep: GRE

394 97410
Q:

A can do a piece of work in 10 days, B in 15 days. They work together for 5 days, the rest of the work is finished by C in two more days. If they get Rs. 3000 as wages for the whole work, what are the daily wages of A, B and C respectively (in Rs):

A) 200, 250, 300 B) 300, 200, 250
C) 200, 300, 400 D) None of these
 
Answer & Explanation Answer: B) 300, 200, 250

Explanation:

A's 5 days work = 50%  

B's 5 days work = 33.33% 

C's 2 days work = 16.66%     [100- (50+33.33)] 

Ratio of contribution of work of A, B and C = 50 : 3313 : 1623 = 3 : 2 : 1   

A's total share = Rs. 1500 

B's total share = Rs. 1000 

C's total share = Rs. 500  

 

A's one day's earning = Rs.300  

B's one day's earning = Rs.200  

C's one day's earning = Rs.250

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

597 96877
Q:

(a - b)2 + 2ab = ?

 

A) a2 - b2 B) a2 + b2
C) a2 - 4ab + b2 D) a2 -  2ab + b2
 
Answer & Explanation Answer: B) a2 + b2

Explanation:
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Filed Under: Simplification
Exam Prep: Bank Exams

4 96391
Q:

What is the next number in the following number series

3, 5, 8, 15, 28, 51, ?

A) 98 B) 102
C) 87 D) 79
 
Answer & Explanation Answer: A) 98

Explanation:

The given number series is 

3, 5, 8, 15, 28, 51, ?

Here the pattern it follows is

3

3 + 2 = 5 ( add prime number less than 3 i.e, 2)

5 + 3 = 8 (3 is prime number less than 5)

8 + 7 = 15 (7 is prime number less than 8)

15 + 13 = 28 (13 is prime number less than 15)

28 + 23 = 51 (23 is prime number less than 28)

51 + 47 = 98 (47 is prime number less than 51)

 

Hence, the next number in the given number series is 98.

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Filed Under: Odd Man Out
Exam Prep: AIEEE , Bank Exams , CAT , GATE , GRE
Job Role: Analyst , Bank Clerk , Bank PO

8 96202
Q:

Find the Odd one out of the given series

6, 15, 35, 77, 165, 221

A) 221 B) 165
C) 35 D) 77
 
Answer & Explanation Answer: B) 165

Explanation:

The terms of the series are products of two consecutive prime numbers i.e.

(2 x 3), (3 x 5), (5 x 7), (7 x 11),.....

So, 165 is wrong and must be replaced by (11 x 13) i.e. 143.

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Filed Under: Odd Man Out
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

16 96046
Q:

At what time between 4 and 5 o'clock will the hands of a watch point in opposite directions?

A) 54 past 4 B) (53 + 7/11) past 4
C) (54 + 8/11) past 4 D) (54 + 6/11) past 4
 
Answer & Explanation Answer: D) (54 + 6/11) past 4

Explanation:

4 o'clock, the hands of the watch are 20 min. spaces apart.
To be in opposite directions, they must be 30 min. spaces apart.
Minute hand will have to gain 50 min. spaces.
55 min. spaces are gained in 60 min 

 

50 min. spaces are gained in 6055×50 min. or 54611 

 

Required time = 54611 min. past 4.

 

 

 

 

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Filed Under: Clocks
Exam Prep: AIEEE , Bank Exams
Job Role: Analyst , Bank Clerk , Bank PO

325 95185
Q:

Simplify the following :

4 15 × 3 13 + ? = 20% of 120

A) 10 B) 24
C) 36 D) 40
 
Answer & Explanation Answer: A) 10

Explanation:

Given equation can be written as

215 x 103 + ? = 24=> 14 + ? = 24=> ? = 24 - 14=> ? = 10

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Filed Under: Simplification
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Analyst , Bank Clerk , Bank PO

1 95156