Time and Work - Quantitative Aptitude (MCQ) questions

1)   Ramesh can complete a work in 12 days, working 7 hours a day. Suresh can complete the same work in 8 days, working 9 hours a day. If Ramesh and Suresh work together working 7 hours a day, in how many days can they complete the work?
- Published on 07 Apr 16

a. 7 * 3 / 23
b. 5 * 7 / 13
c. 6 * 5 / 13
d. 6 * 6 / 11
e. None of these
Answer  Explanation 

ANSWER: 5 * 7 / 13

Explanation:
Ramesh can finish the work in 12 * 7 = 84 hours
Amount of work he can complete in 1 hour = 1/84
Suresh can finish the same work in 8 * 9 = 72 hours
Amount of work he can complete in 1 hour = 1/72 hours
Work done by both of them in 1 hour =
= 1/84 + 1/72 = 13/504
Ramesh and Suresh together can complete the work in 504/13 hours.
i.e. 504/13 * 1/7 = 72/13 days
i.e. 5 * 7 / 13 days


2)   An employer pays Rs. 30 for each day a worker works, and forfeits Rs. 5 for each day he is idle. At the end of 60 days, a worker gets Rs. 500. For how many days did the worker remain idle?
- Published on 06 Apr 16

a. 35
b. 48
c. 52
d. 58
Answer  Explanation 

ANSWER: 52

Explanation:
Suppose the worker remained idle for m days. Then, he worked for (60 - m) days.
30 (60 - m) – 5m = 500
1800 – 25m = 500
25m = 1300
m = 52
So, the worker remained idle for 52 days.


3)   A man can do a piece of work in 4 days, but with the help of his daughter, he can do it in 3 days. In what time can his daughter do it alone?
- Published on 06 Apr 16

a. 6 ½ days
b. 7 days
c. 9 ½ days
d. 12 days
Answer  Explanation 

ANSWER: 12 days

Explanation:
Daughter’s 1 day’s work = (1/3 – 1/4) = 1/12
Daughter alone can do the work in 12/1 = 12 days


4)   P and Q together can complete a piece of work in 4 days. If P alone can complete the same work in 20 days, in how many days can Q alone complete that work?
- Published on 28 Mar 16

a. 8
b. 7
c. 4
d. 5
Answer  Explanation 

ANSWER: 5

Explanation:
(P + Q)'s 1 day's work = 1/4, P's 1 day's work = 1/20
Q's 1 day's work = (1/4 – 1/20) = (4/20) = (1/5)
Hence, Q alone can complete the work in 5 days.


5)   If 10 bulls can plough 20 identical fields in 3 days working 10 hours a day, then in how many days can 30 bulls plough 32 same identical fields working 8 hours a day?
- Published on 06 Jul 15

a. 2
b. 4
c. 8
d. 10
Answer  Explanation 

ANSWER: 2

Explanation:
M1*D1*W2 = M2*D2*W1
10*3*10*32 = 30*d*8*20
d = 2 days


6)   A can build a wall in the same time in which B and C together can do it. If A and B together could do it in 25 days and C alone in 35 days, in what time could B alone do it?
- Published on 15 Jun 15

a. 175 days
b. 100 days
c. 90 days
d. None of these
Answer  Explanation 

ANSWER: 175 days

Explanation:
No explanation is available for this question!


7)   A pack of people can complete a certain amount of work in 12 days. Two times the same number of persons will complete half of the work in?
- Published on 15 Jun 15

a. 12 days
b. 3 days
c. 4 days
d. 6 days
Answer  Explanation 

ANSWER: 3 days

Explanation:
More no of people: Less days (Inverse Relationship)

More work: More days (Direct Relationship)

Ratio is given:

Persons: 1 :: 2
Work 1 :: 1/2
Time 12 :: x

Solution of this can be explained by solving this ratio by the sort of relationships they possess with time.

1*1/2*12 = 2*1*x

=> x = 3 days


8)   12 men and 18 boys working 7.5 minutes an hour complete a particular piece of work in 60 hours. If a boy’s work is half as efficient as a man’s work, how many boys will be needed to help 21 men to achieve twice the work in 50 hours working 9 minutes in an hour.
- Published on 15 Jun 15

a. 42
b. 46
c. 48
d. 38
Answer  Explanation 

ANSWER: 42

Explanation:
1 man is equivalent to 2 boys in work capacity. 12 men + 18 boys = 12 x 2 + 18 = 42 boys.

Let the required number of boys be x. So Total number of people doing work = 21 men x 2 (according to work capacity) + x boys.

Taking respective ratios as required:

Given:

=> Hours 50:60
=> Minutes per hour 9: 15/2
=> Work 1:2
=> People: 42: 42 + x
=> 50 x 9 x 1 x (42+x) = 60 x 15/2 x 2 x 42
=> 42 +x = 84

x = 42


9)   A car consumes 210 liters of petrol weekly. For how many days will 1470 liters of petrol be sufficient?
- Published on 12 Jun 15

a. 48
b. 49
c. 50
d. 52
Answer  Explanation 

ANSWER: 49

Explanation:
No explanation is available for this question!


10)   5/8th of a job is completed in 10 days. If a person works at the same pace, how many days will he take to complete the job?
- Published on 19 Oct 15

a. 4
b. 5
c. 6
d. 7
Answer  Explanation 

ANSWER: 6

Explanation:
Solution: It is given that 5/8th of the work is completed in 10 days.

=> Remaining work = 3/8th of total

Applying unitary method:

Total work will be completed in 10 * 8 / 5 days

=> It takes 16 days to complete total work

=> Hence, remaining work days = 16 - 10 = 6 days


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