Formulae
1. Work Done = Time Taken × Rate of Work
2. Rate of Work = 1 / Time Taken
3. Time Taken = 1 / Rate of Work
4. If a piece of work is done in x number of days, then the work done in one day = 1/x
5. Total Wok Done = Number of Days × Efficiency
6. Efficiency and Time are inversely proportional to each other
7. X:y is the ratio of the number of men which are required to complete a piece of work, then the ratio of the time taken by them to complete the work will be y:x
8. If x number of people can do W1 work, in D1 days, working T1 hours each day and the number of people can do W2 work, in D2 days, working T2 hours each day, then the relation between them will be
(M1 x D1 x T1)/W1 = (M2 x D2 x T2)/W2
Exercise : Time and Work MCQ Questions and Answers
Question 1
Five men and nine women can do a piece of work in 10 days. Six men and twelve women can do the same work in 8 days. In how many days can three men and three women do the work?
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Correct Answer : D. 20
Description :
(5m + 9w)10 = (6m + 12w)8
=> 50m + 90w = 48w + 96 w => 2m = 6w => 1m = 3w 5m + 9w = 5m + 3m = 8m
8 men can do the work in 10 days.
3m +3w = 3m + 1w = 4m
So, 4 men can do the work in (10 * 8)/4 = 20 days.
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Question 2
A, B and C can complete a piece of work in 24, 6 and 12 days respectively. Working together, they will complete the same work in
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Correct Answer : B. 24/7 days
Description :
Formula: If A can do a piece of work in n days, then A's 1 day's work = 1/n .
(A + B + C)'s 1 day's work = 1/24 + 1/6 + 1/12 = 7/24
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Formula: If A's 1 day's work = 1/n , then A can finish the work in n days.
So, all the three together will complete the job in 24/7 days
Question 3
A and B can do a piece of work in 30 days, while B and C can do the same work in 24 days and C and A in 20 days. They all work together for 10 days when B and C leave. How many days more will A take t
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Correct Answer : A. 18 days
Description :
2 ( A + B + C) 's 1 day's work = 1/30 + 1/24 + 1/20 = 1/8
their 1 day's work = 1/8/2 = 1/16
their 10 days work = 1/16 × 10 = 5/8
the remaining work = 3/8
A's 1 day's work = 1/16 – 1/24 = 1/48
Therefore, the No. of days A alone will take to complete 3/8 of the work = 3/8/ 1/48
= 3/8 × 48 = 3 × 6 = 18 days.
Question 4
Two persons A and B can complete a piece of work in 30 days and 45 days respectively. If they work together, what part of the work will be completed in 3 days?
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Correct Answer : B. 1/6
Description :
A's one day's work = 1/30
B's one day's work = 1/45
(A + B)'s one day's work = 1/30 + 1/45 = 1/18
The part of the work completed in 3 days = 3 (1/18) = 1/6.
Question 5
Two persons, Rahul and Manoj, undertake a work for Rs. 9000. Rahul alone can do the work in 16 days and Manoj alone can do it in 24 days. If, with the assistance of a third person Niraj, they finish t
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Correct Answer : A. Rs. 1500
Description :
Rahul's eight day's work + Manoj's eight day's work + Niraj's three day's work = 1
∴ 8/16 + 8/24 + Niraj's eight day's work = 1
∴ Niraj's eight day's work = 1 - (1/2 + 1/3) = 1/6
∴ Ratio of their shares= 8/16 : 8/24 : 1/6 = 1/2 : 1/3 : 1/6
∴ Reqd ratio = 3 : 2 : 1
So, Niraj's share = 9000/6 x 1 = 1500
Question 6
9 men working 7 hours a day can complete a piece of work in 15 days. How many days can 6 men working for 9 hours a day, complete the same piece of work?
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Correct Answer : D. 17 ? days
Description :
1 work done = 9 ? 7 ? 15
9 ? 7 ? 15 = 6 ? 9 ? ? days
? days = 9 ? 7 ? 15/6 ? 9
= 35/2 = 17 ? days.
Question 7
12 men can complete a work in 8 days. 16 women can complete the same work in 12 days. 8 men and 8 women started working and worked for 6 days. How many more men are to be added to complete the remain
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Correct Answer : B. 12
Description :
No answer description available for this question. Let us discuss.
Question 8
There is a sufficient food for 200 men for 20 days after 15 days 100 men leave the place. For how many days will the rest of the food last for the rest of the men?
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Correct Answer : D. 10 days
Description :
After 13 days , 100 men left,
Therefore 5 days*200 men =x days*100men
X = 10 days
Question 9
How many packets do 2 machines pack in one day ? I Each machine runs for 12 hours daily. II 5 machines pack 10000 packets in 5 days.
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Correct Answer : D. If the question can be answered by using statement (II) alone but cant be answered by using statement (I) alone.
Description :
If the question can be answered by using statement (II) alone but cant be answered by using statement (I) alone.
Question 10
A and B together can complete a particular task in 4 days. If A alone can complete the same task in 12 days. How many days will B take to complete the task if he works alone?
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Correct Answer : B. None of these
Description :
No answer description available for this question. Let us discuss.