Quantitative Aptitude
Time, Work, and Projects
190 Questions
Time and work questions test the ability to calculate the time required to complete tasks involving individual or combined worker efficiency. These problems frequently appear in competitive exams to assess logical calculation skills. Topics include pipes, cisterns, group efficiency, and hourly work rates.
Combined work efficiencyMen and days calculationsWorker efficiency ratiosWorking hours per dayLeaving and joining workers
Time, Work, and Projects Questions
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40 days
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35 days
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30 days
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60 days
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None of these
D
Correct answer
Explanation
Pradeep and Dipali's 1 day's work = 1/10
Dipali's 1 day's work = 1/12
Therefore, Pradeep's 1 day's work = 1/10 - 1/12 = 2/120 = 1/60
Number of days required to do the work by Pradeep = 60 days
Hence, this option is correct.
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4
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2.25
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10
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9
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None of these
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1/6 days
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1/5 days
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5 days
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6 days
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None of these
C
Correct answer
Explanation
(A + B)'s 1 day work = 11/30
A's 1 day work = 1/6
Therefore, B's 1 day work = 11/30 - 1/6 = 6/30 = 1/5
Therefore, B alone can do the same work in = 5 days
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2.3
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2.1
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10/24
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2.4
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None of these
D
Correct answer
Explanation
A's 1 day work = 1/4
B's 1 day work = 1/6
(A + B)'s 1 day work = (1/6 + 1/4) = 10/24
Therefore, required number of days = 24/10 = 2.4
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10 days
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13 days
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12 days
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Data inadequate
C
Correct answer
Explanation
(Work done by both in one day = 1 รท 7.5 = 2/15 Work done by Salim in one day = 1/20. Therefore, work done by Akram in one day = 2/15 - 1/20 = 8 - 3/60 = 5/60 = 1/12. Hence Akram alone can do the work in 12 days.)
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4 : 1
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2 : 7
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8 : 3
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7 : 2
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None of these
D
Correct answer
Explanation
(2 men + 3 boys can do a job in 5 days, so in one day-5 X (2 men + 3 boys) can do it in one day. Similarly, 4 X (3 men + 2 boys) can do it in one day. Therefore, 5 X (2 men + 3 boys) = 4 X (3 men + 2 boys)2 men = 7 boys. Hence, work ratio = 7 : 2)
D
Correct answer
Explanation
Work rates: A=1/7, B=1/8, C=1/6. Cycle (3 days) = 1/7 + 1/8 + 1/6 = (24+21+28)/168 = 73/168. After 6 days (2 cycles) = 146/168. Remaining = 22/168. Day 7 (Anand) does 1/7 = 24/168. Since 24/168 > 22/168, work finishes on day 7.
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Greg
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Dan
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Tom
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All of the above
A
Correct answer
Explanation
Greg completed the homework in 15 minutes.
Tom completed the homework in 1 hour, i.e. 60 minutes.
Dan completed the homework in half hour, i.e. 30 minutes.
15 minutes is the shortest time duration. So, Greg completed the homework in the shortest time duration.
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210 days
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425/12 days
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410 days
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205/6 days
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425 days
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124/3 days
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31/18 days
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360/13
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180/13
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124/3 hours
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300/13 days
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415/6 days
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207/3
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276/4
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None of these
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12 days
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51/2 hours
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51/2 days
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5 days
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25 days
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10 hours
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5/12 days
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5 hours
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5/24 days
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None of these
B
Correct answer
Explanation
Use unitary method
ab = 12 = 5 unit out of lcm of time 60
bc =15 = -4ca = 20 = 32abc = 4abc = 2
So, a = 6b = -1c = -3
So, 10 hour = 5 /12 day
This is correct.
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30 days
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30 hours
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5/4 days
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15 hours
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15 days
C
Correct answer
Explanation
a + b = 5 unit/hour
b + c = -4c + a = 32(abc) = 4abc = 2 units in hours means 30 hours to complete = 30/24 days
This is correct.
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5/12 days
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10 hours
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30 days
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5/4 days
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15/4 days
E
Correct answer
Explanation
in three days, 2 unit of total work = lcm of time = 60 unit
So, time taken = 60/2 * 3 = 90 hours
This answer is correct.