Time and Work MCQs

Maths

Time and Work MCQs

Practice Time and Work MCQs with answers and detailed solutions. Learn work efficiency, pipes and cisterns, men and women work problems, partnership, wages, productivity and advanced aptitude questions commonly asked in competitive exams.

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Question #41
Two workers A and B are engaged to do a piece of work. Working together they would take 8 hours less than the time taken by A alone, and 4.5 hours less than the time taken by B alone. Find the time they take to complete the work together.
A. 8 hours
B. 6 hours
C. 7 hours
D. 5 hours

Correct Answer: Option B


Explanation:
Let the time taken together be t hours. Then A takes (t + 8) hours and B takes (t + 4.5) hours. Using the direct formula for such problems: t = sqrt(a * b), where a and b are the extra times. t = sqrt(8 * 4.5) = sqrt(36) = 6 hours.

This question belongs to: Maths Time and Work
Question #42
If 6 men and 8 boys can do a piece of work in 10 days while 26 men and 48 boys can do the same in 2 days, the time taken by 15 men and 20 boys in doing the same type of work will be:
A. 6 days
B. 5 days
C. 7 days
D. 4 days

Correct Answer: Option D


Explanation:
Total work = 10 * (6M + 8B) = 2 * (26M + 48B) => 60M + 80B = 52M + 96B => 8M = 16B => 1M = 2B. Total work in terms of boys = 10 * (6*2B + 8B) = 10 * 20B = 200 boy-days. Efficiency of 15 men and 20 boys = 15*2B + 20B = 50B. Time taken = 200 / 50 = 4 days.

This question belongs to: Maths Time and Work
Question #43
A can finish a work in 24 days, B in 9 days and C in 12 days. B and C start the work but are forced to leave after 3 days. The remaining work was done by A in:
A. 5 days
B. 6 days
C. 10.5 days
D. 10 days

Correct Answer: Option D


Explanation:
Total work = LCM(24, 9, 12) = 72 units. Efficiency of A = 3, B = 8, C = 6. B and C work for 3 days: work done = 3 * (8 + 6) = 3 * 14 = 42 units. Remaining work = 72 - 42 = 30 units. Time taken by A to complete remaining work = 30 / 3 = 10 days.

This question belongs to: Maths Time and Work
Question #44
A group of men decided to do a work in 10 days, but 5 of them became absent. If the rest of the group did the work in 12 days, find the original number of men.
A. 30
B. 40
C. 35
D. 25

Correct Answer: Option A


Explanation:
Let the original number of men be x. Using M1 * D1 = M2 * D2: x * 10 = (x - 5) * 12 => 10x = 12x - 60 => 2x = 60 => x = 30.

This question belongs to: Maths Time and Work
Question #45
A is thrice as efficient as B. Working together, they can complete a piece of work in 18 days. In how many days can A alone complete the work?
A. 54 days
B. 24 days
C. 72 days
D. 36 days

Correct Answer: Option B


Explanation:
Let B's efficiency = 1, then A's efficiency = 3. Combined efficiency = 3 + 1 = 4. Total work = 18 * 4 = 72 units. Time taken by A alone = 72 / 3 = 24 days.

This question belongs to: Maths Time and Work
Question #46
A can do a piece of work in 40 days. He works at it for 8 days and then B finishes it in 16 days. How long will A and B together take to complete the work?
A. 13(1/3) days
B. 20 days
C. 15 days
D. 25 days

Correct Answer: Option A


Explanation:
Let total work be 40 units. Efficiency of A = 1 unit/day. In 8 days, A completes 8 units. Remaining work = 40 - 8 = 32 units. B finishes 32 units in 16 days, so B's efficiency = 32 / 16 = 2 units/day. Combined efficiency of A and B = 1 + 2 = 3 units/day. Time taken together = 40 / 3 = 13(1/3) days.

This question belongs to: Maths Time and Work
Question #47
A and B together can complete a piece of work in 12 days. They worked together for 4 days and then A left. B finished the remaining work alone in 14 more days. In how many days can A alone complete the work?
A. 35 days
B. 42 days
C. 28 days
D. 21 days

Correct Answer: Option C


Explanation:
Let combined efficiency of A and B be 1 unit/day, so total work = 12 units. In 4 days, they complete 4 units. Remaining work = 12 - 4 = 8 units. B completes 8 units in 14 days, so B's efficiency = 8 / 14 = 4/7 units/day. Efficiency of A = 1 - 4/7 = 3/7 units/day. Time taken by A alone = 12 / (3/7) = (12 * 7) / 3 = 28 days.

This question belongs to: Maths Time and Work
Question #48
A is 50% more efficient than B. C does half of the work done by A and B together in the same time. If C alone can do the work in 40 days, then A, B and C together can do the work in:
A. 20 days
B. 15 days
C. 13(1/3) days
D. 30 days

Correct Answer: Option C


Explanation:
Let efficiency of B = 2, then efficiency of A = 3. Combined efficiency of A and B = 5. Efficiency of C = 5 / 2 = 2.5. Total work = Efficiency of C * Time taken by C = 2.5 * 40 = 100 units. Combined efficiency of A, B and C = 3 + 2 + 2.5 = 7.5 units/day. Time taken together = 100 / 7.5 = 1000 / 75 = 40 / 3 = 13(1/3) days.

This question belongs to: Maths Time and Work
Question #49
10 men can complete a work in 7 days. But 10 women can complete the same work in 14 days. If 5 men and 10 women work together, in how many days will the work be completed?
A. 6 days
B. 8 days
C. 7 days
D. 5 days

Correct Answer: Option C


Explanation:
Efficiency of 10 men = 1/7, so 1 man = 1/70. Efficiency of 10 women = 1/14. Efficiency of 5 men and 10 women = 5*(1/70) + 1/14 = 1/14 + 1/14 = 2/14 = 1/7. Thus, they will complete the work in 7 days.

This question belongs to: Maths Time and Work
Question #50
A and B can complete a piece of work in 18 days and 24 days respectively. They worked together for 6 days and then A left. In how many days will B complete the remaining work?
A. 14 days
B. 8 days
C. 10 days
D. 12 days

Correct Answer: Option C


Explanation:
Total work = LCM(18, 24) = 72 units. Efficiency of A = 4, B = 3. Combined efficiency = 7. In 6 days, work done = 6 * 7 = 42 units. Remaining work = 72 - 42 = 30 units. Time taken by B to finish remaining work = 30 / 3 = 10 days.

This question belongs to: Maths Time and Work
Question #51
A can do a piece of work in 80 days. He works at it for 10 days and then B alone finishes the remaining work in 42 days. In how many days can A and B together complete the work?
A. 35 days
B. 24 days
C. 30 days
D. 25 days

Correct Answer: Option C


Explanation:
Let total work be 80 units. Efficiency of A = 1 unit/day. In 10 days, A completes 10 units. Remaining work = 80 - 10 = 70 units. B finishes 70 units in 42 days, so B's efficiency = 70 / 42 = 5/3 units/day. Combined efficiency of A and B = 1 + 5/3 = 8/3 units/day. Time taken together = 80 / (8/3) = (80 * 3) / 8 = 30 days.

This question belongs to: Maths Time and Work
Question #52
A can do a piece of work in 10 days, B in 12 days and C in 15 days. They carry out the work together and get a total of Rs. 6000 as wages. Find the share of A.
A. Rs. 2000
B. Rs. 2500
C. Rs. 1800
D. Rs. 2400

Correct Answer: Option D


Explanation:
Total work = LCM(10, 12, 15) = 60 units. Efficiency of A = 6, B = 5, C = 4. Ratio of wages is equal to ratio of efficiencies = 6 : 5 : 4. Total ratio parts = 6 + 5 + 4 = 15. Share of A = (6 / 15) * 6000 = 6 * 400 = Rs. 2400.

This question belongs to: Maths Time and Work
Question #53
A, B and C can do a piece of work in 20, 30 and 60 days respectively. If A works everyday and is assisted by B and C together on every third day, then in how many days will the work be completed?
A. 20 days
B. 15 days
C. 18 days
D. 12 days

Correct Answer: Option B


Explanation:
Total work = LCM(20, 30, 60) = 60 units. Efficiency of A = 3, B = 2, C = 1. Day 1: A works = 3 units. Day 2: A works = 3 units. Day 3: A+B+C work = 3 + 2 + 1 = 6 units. Work done in 3 days = 3 + 3 + 6 = 12 units. Number of 3-day cycles to complete 60 units = 60 / 12 = 5 cycles. Total days = 5 * 3 = 15 days.

This question belongs to: Maths Time and Work
Question #54
A and B can complete a piece of work in 12 and 18 days respectively. They begin the work together, but A leaves 4 days before the completion of the work. For how many days did A and B work together?
A. 5.6 days
B. 4.4 days
C. 5 days
D. 6 days

Correct Answer: Option A


Explanation:
Total work = LCM(12, 18) = 36 units. Efficiency of A = 3, B = 2. Let total days be x. B works for x days, A works for (x - 4) days. 3(x - 4) + 2x = 36 => 3x - 12 + 2x = 36 => 5x = 48 => x = 9.6 days. A and B worked together for x - 4 = 9.6 - 4 = 5.6 days.

This question belongs to: Maths Time and Work
Question #55
If 12 men and 16 boys can do a piece of work in 5 days; while 13 men and 24 boys can do it in 4 days, then the ratio of the daily work done by a man to that of a boy is:
A. 3 : 2
B. 5 : 4
C. 3 : 1
D. 2 : 1

Correct Answer: Option D


Explanation:
Total work = 5 * (12M + 16B) = 4 * (13M + 24B) => 60M + 80B = 52M + 96B => 8M = 16B => M/B = 16/8 = 2/1. Thus, the ratio is 2 : 1.

This question belongs to: Maths Time and Work
Question #56
A can do a piece of work in 25 days and B can finish it in 20 days. They work together for 5 days and then A leaves. In how many days will B finish the remaining work?
A. 9 days
B. 10 days
C. 12 days
D. 11 days

Correct Answer: Option D


Explanation:
Total work = LCM(25, 20) = 100 units. Efficiency of A = 4, B = 5. Combined efficiency = 9 units/day. In 5 days, work done = 5 * 9 = 45 units. Remaining work = 100 - 45 = 55 units. Time taken by B to complete remaining work = 55 / 5 = 11 days.

This question belongs to: Maths Time and Work
Question #57
X can do a piece of work in 40 days. He works at it for 8 days and then Y alone finishes the remaining work in 16 days. How long will X and Y together take to complete the work?
A. 13(1/3) days
B. 16 days
C. 14 days
D. 15 days

Correct Answer: Option A


Explanation:
Let total work be 40 units. Efficiency of X = 1 unit/day. In 8 days, X completes 8 units. Remaining work = 40 - 8 = 32 units. Y finishes 32 units in 16 days, so Y's efficiency = 32 / 16 = 2 units/day. Combined efficiency of X and Y = 1 + 2 = 3 units/day. Time taken together = 40 / 3 = 13(1/3) days.

This question belongs to: Maths Time and Work
Question #58
A and B can do a work in 8 days, B and C in 12 days and A, B, C together in 6 days. In how many days can A and C together complete the work?
A. 10 days
B. 6 days
C. 4 days
D. 8 days

Correct Answer: Option D


Explanation:
Total work = LCM(8, 12, 6) = 24 units. Efficiency of (A+B) = 3, (B+C) = 2, (A+B+C) = 4. Efficiency of C = (A+B+C) - (A+B) = 4 - 3 = 1. Efficiency of A = (A+B+C) - (B+C) = 4 - 2 = 2. Combined efficiency of A and C = 2 + 1 = 3. Time taken by A and C together = 24 / 3 = 8 days.

This question belongs to: Maths Time and Work
Question #59
A can finish a work in 15 days and B in 25 days. They start together but B leaves 5 days before the completion of the work. Find the total number of days taken to complete the work.
A. 11.25 days
B. 10 days
C. 13.25 days
D. 12.5 days

Correct Answer: Option A


Explanation:
Total work = LCM(15, 25) = 75 units. Efficiency of A = 5, B = 3. Let total days be x. A works for x days, B works for (x - 5) days. 5x + 3(x - 5) = 75 => 8x - 15 = 75 => 8x = 90 => x = 90/8 = 11.25 days.

This question belongs to: Maths Time and Work
Question #60
If 3 men or 4 women can plow a field in 43 days, how long will 7 men and 5 women take to plow it?
A. 15 days
B. 8 days
C. 10 days
D. 12 days

Correct Answer: Option D


Explanation:
3 Men = 4 Women => 1 Man = 4/3 Women. 7 men + 5 women = 7 * (4/3) + 5 = 28/3 + 5 = 43/3 women. Since 4 women take 43 days, 43/3 women will take (4 * 43) / (43/3) = 4 * 3 = 12 days.

This question belongs to: Maths Time and Work