Quantitative Aptitude

Time and Work

2,195 Questions
All Pairwise rates and staged schedules 440 Workers-days-hours chain rule 439 LCM units and efficiency ratios 409 Different worker categories 311 Combined rates and an unknown worker 257 Division of wages 219 Alternate work 110 Opposing rates 10

Time and Work Questions

Multiple choice

A can do a piece of work in 6 days and B can do the same work in 8 days. A and B agrees to do it for Rs. 320. With the help of C, they managed to finish the work in 3 days. Find the amount of money A and B paid to C.

  1. Rs. 37.50

  2. Rs. 40

  3. Rs. 60

  4. Rs. 80
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A's rate = 1/6, B's rate = 1/8. In 3 days, A does 3/6 = 1/2, B does 3/8. Total work by A+B = 1/2 + 3/8 = 7/8. C does 1 - 7/8 = 1/8 of the work. C's share = (1/8) * 320 = 40.

Multiple choice

6 men can complete a piece of work in 12 days. 8 women can complete the same piece of work in 18 days whereas 18 children can complete the piece of work in 10 days. 4 men, 12 women and 20 children work together for 2 days. If only men were to complete the remaining work in 1 day, how many men would be required totally?

  1. 36

  2. 24

  3. 18

  4. Cannot be determined

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Calculate the work rates: 1 man = 1/72 work/day, 1 woman = 1/144 work/day, 1 child = 1/180 work/day. In 2 days, 4 men, 12 women, and 20 children complete 2 * (4/72 + 12/144 + 20/180) = 2 * (1/18 + 1/12 + 1/9) = 2 * (2/36 + 3/36 + 4/36) = 2 * (9/36) = 0.5 work. Remaining work is 0.5. To finish in 1 day, 0.5 / (1/72) = 36 men are required.

Multiple choice

Four men A, B, C and D can do a piece of work in 20 days, 30 days, 40 days and 60 days, respectively. A and B work together for 8 days and C and D work together for 5 days. The remaining work is completed by E, a new person. For the work completed, they all together get some money. How much more money does E get than C, if total amount paid to all the five is Rs. 2400?

  1. Rs. 0

  2. Rs. 500

  3. Rs. 800

  4. Rs. 1,000

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Work done by A and B in 8 days: 8 * (1/20 + 1/30) = 8 * (5/60) = 2/3. Work done by C and D in 5 days: 5 * (1/40 + 1/60) = 5 * (5/120) = 5/24. Total work done = 2/3 + 5/24 = 21/24 = 7/8. Remaining work = 1/8. Since E does 1/8 of the work, and C does 5/40 = 1/8, they do the same amount of work and get the same pay.

Multiple choice

A man does the first half of a piece of work three times faster than he does the second half. If he had done the second half also at the same rate as first, the work would have been completed 15 days earlier. In how many days has he actually completed the work?

  1. 30 days

  2. 35 days

  3. 25 days

  4. 40 days

  5. Cannot be determined
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let total work be 2 units. First half (1 unit) takes time t1, second half (1 unit) takes t2. Rate1 = 3 * Rate2, so t2 = 3 * t1. Total time = t1 + 3t1 = 4t1. If second half was done at Rate1, time would be t1 + t1 = 2t1. 4t1 - 2t1 = 15 days, so 2t1 = 15, t1 = 7.5. Total time = 4 * 7.5 = 30 days.

Multiple choice

A is twice as efficient as B and B is twice as efficient as C. If A, B and C work together, a piece of work will be completed in 12 days. A and B work together for 8 days and thereafter, A is replaced by C. How many more days are required to complete the work?

  1. 8 days

  2. 10 days

  3. 12 days

  4. 15 days

  5. 16 days
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Efficiency: A=4, B=2, C=1. Total work = (4+2+1)*12 = 84 units. A+B work for 8 days: (4+2)*8 = 48 units. Remaining work = 84-48 = 36 units. A is replaced by C, so B+C work: (2+1) = 3 units/day. Days required = 36/3 = 12 days.