Quantitative Aptitude - Arithmetic Ability Questions

Q:

Two pipes A and B can fill a cistern in 4 minutes and 6 minutes respectively . If these pipes are turned on alternately for 1 minute each how long will it take to the cistern to fill?

Answer

As the pipes are operating alternatively, thus their 2 minutes job is = 14 + 16 = 512 


In the next 2 minutes the pipes can fill another 512 part of cistern. 


Therefore, In 4 minutes the two pipes which are operating alternatively will fill 512 + 512 = 56Remaining part = 1 - 56 = 16 


Pipe A can fill 14 of the cistern in 1 minute 


Pipe A can fill 16 of the cistern in = 23 min 


Therefore, Total time taken to fill the Cistern  


4 + 23 minutes.

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

28 14746
Q:

A cube of edge 15 cm is immersed completely in a rectangular vessel containing water . If the dimensions of the base of vessel are 20 cm x 15 cm, find the rise in water level

 

A) 11.25cm B) 11.56cm
C) 11.66cm D) 10.86cm
 
Answer & Explanation Answer: A) 11.25cm

Explanation:

Increase in volume = Volume of the cube = (15 x 15 x 15) cm3.

 

\Rise in water level = volume/area = (15 x 15 x 15)/(20 x 15) cm = 11.25 cm.

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7 14740
Q:

If n is natural number , then 6n2+6n is always divisible by :

A) 6 only B) 6 and 12 both
C) 12 only D) by 18 only
 
Answer & Explanation Answer: B) 6 and 12 both

Explanation:

6n2+6n=6nn+1, which is always divisible by 6 and 12 both, since n(n+1) is always even.

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Filed Under: Numbers

12 14737
Q:

12 men complete a work in 9 days. After they have worked for 6 days, 4 more men join them. How many days will they take to complete the remaining work ?

A) 2 days B) 2.5 days
C) 2.25 days D) 3 days
 
Answer & Explanation Answer: C) 2.25 days

Explanation:

1 man's 1 day work = 1/108
12 men's 6 day's work = 1/9 x 6 = 2/3

Remaining work = 1 - 2/3 = 1/3

16 men's 1 day work = 1/108 x 16 = 4/27
4/27 work is done by them in 1 day.

1/3 work is done by them in 27/4 x 1/3 = 9/4 days.

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

18 14725
Q:

If nC10=nC12  then,find n.

A) 10 B) 12
C) 22 D) 24
 
Answer & Explanation Answer: C) 22

Explanation:

Using, Crn=Cn-rn we get 

n – 10 = 12

or, n = 12 + 10 = 22

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19 14718
Q:

One year ago the ratio between Maneela’s and Shanthi’s salary was 3 : 4. The ratios of their individual salaries between last year’s and this year’s salaries are 4 : 5 and 2 : 3 respectively. At present the total of their salary is Rs. 4160. The salary of Maneela, now is?

A) Rs. 1600 B) Rs. 1700
C) Rs. 1800 D) Rs. 1900
 
Answer & Explanation Answer: A) Rs. 1600

Explanation:

Let the salaries of Maneela and Shanthi one year before be M1, S1 & now be M2, S2 respectively.

Then, from the given data,

M1/S1 = 3/4  .....(1)

M1/M2 = 4/5 .....(2)

S1/S2 = 2/3  .....(3)

and M2 + S2 = 4160  .....(4)

 

Solving all these eqtns, we get M2 = Rs. 1600.

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47 14700
Q:

P, Q, and R can do a job in 12 days together.  If their efficiency of working be in the ratio 3 : 8 : 5, Find in what time Q can complete the same work alone?

A) 36 days B) 30 days
C) 24 days D) 22 days
 
Answer & Explanation Answer: A) 36 days

Explanation:

Given the ratio of efficiencies of P, Q & R are 3 : 8 : 5

Let the efficiencies of P, Q & R be 3x, 8x and 5x respectively

They can do work for 12 days.

=> Total work = 12 x 16x = 192x

 

Now, the required time taken by Q to complete the job alone = 162x8x = 24 days.

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17 14658
Q:

A man invested Rs. 1552 in a stock at 97 to obtain an income of Rs. 128. The dividend from the stock is:

A) 8.5% B) 7.5%
C) 8% D) 9%
 
Answer & Explanation Answer: C) 8%

Explanation:

By investing Rs. 1552, income = Rs. 128.

 

By investing Rs. 97, income =Rs.1281552×97= Rs. 8.

 

Dividend = 8%

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Filed Under: Stocks and Shares

5 14655