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, B and C can individually complete a piece of work in 20 days, 15 days and 12 days, respectively. B and C start the work and they work for 3 days and leave. Then, the number of days required by A to finish the remaining work is

  1. 11

  2. 14

  3. 12

  4. 9
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A's rate is 1/20, B's is 1/15, C's is 1/12. B and C work for 3 days: 3 * (1/15 + 1/12) = 3 * (4+5)/60 = 27/60 = 9/20. Remaining work = 11/20. A takes (11/20) / (1/20) = 11 days.

Multiple choice

Akashi can do a work in 6 days while Barack can do the same work in 8 days. They both decided to do the work for Rs. 2400. With the help of Charlie, they completed the work in 3 days. How much is to be paid to Charlie?

  1. Rs. 100

  2. Rs. 300

  3. Rs. 400

  4. Rs. 800
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Akashi's rate = 1/6, Barack's rate = 1/8. Combined rate = 1/6 + 1/8 = 7/24. In 3 days, they do 3 * (7/24) = 7/8 of the work. Charlie does 1 - 7/8 = 1/8 of the work. Charlie's pay = (1/8) * 2400 = 300.

Multiple choice

81 men can construct a 200-m long wall in 24 days, working 6 hours a day. If 27 men leave the work after 6 days, then how many hours per day should the remaining men work to complete the work in the remaining days?

  1. 9

  2. 16

  3. 32

  4. 48

  5. 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Work = Men * Days * Hours. Total work = 81 * 24 * 6 = 11664 man-hours. Work done in 6 days = 81 * 6 * 6 = 2916. Remaining work = 11664 - 2916 = 8748. Remaining men = 81 - 27 = 54. Remaining days = 24 - 6 = 18. Hours needed = 8748 / (54 * 18) = 8748 / 972 = 9.

Multiple choice

A and B can do a piece of work in 15 days. B and C together can do it in 24 days. After A worked for 5 days and B worked for 13 days, C took up and finished it in 28 days. In how many days can each of them do the work, working alone?

  1. 24, 40, 60

  2. 28, 32, 68

  3. 183/7, 54, 24

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

Let work rates be A, B, C. A+B = 1/15, B+C = 1/24. 5A + 13B + 28C = 1. Using A = 1/15 - B and C = 1/24 - B: 5(1/15 - B) + 13B + 28(1/24 - B) = 1. Solving for B gives B = 1/40. Then A = 1/24 and C = 1/60. Days are 24, 40, 60.

Multiple choice

A person gives a contract of repairing of his home to two workers A and B with a contract amount of Rs. 13500. If worker A is 3 times more efficient than worker B and they both can complete the work in 45 days, what is the amount paid to worker A for 10 days?

  1. Rs. 2000

  2. Rs. 2500

  3. Rs. 2750

  4. Rs. 2250
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A is 3 times as efficient as B. A = 3B. Combined efficiency (A+B) = 4B. They finish in 45 days, so total work = 4B * 45 = 180B. Amount for A = (Efficiency of A / Total Efficiency) * Total Amount = (3B / 4B) * 13500 = 0.75 * 13500 = 10125 for 45 days. Amount for 10 days = (10125 / 45) * 10 = 225 * 10 = 2250.

Multiple choice

Ramesh and Suresh together can complete a piece of work in 24 days. Suresh and Mahesh together can complete the same work in 16 days. Mahesh and Ramesh together can complete the same work in 12 days. How long would Suresh take to complete the same task working alone?

  1. 96 days

  2. 78 days

  3. 108 days

  4. 88 days

  5. 72 days
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let R, S, M be rates. R+S = 1/24, S+M = 1/16, M+R = 1/12. Adding them: 2(R+S+M) = 1/24 + 1/16 + 1/12 = (2+3+4)/48 = 9/48 = 3/16. So R+S+M = 3/32. To find S, subtract (M+R): S = 3/32 - 1/12 = (9-8)/96 = 1/96. Suresh takes 96 days.

Multiple choice

Sonia can do a job of printing and typing in 18 days. Raman can do the same work in 54 days and Parmit can do the same work in 108 days. If all the three are working together on the work, the total money to be paid for the work is Rs. 7838. If Sonia gets ill after working for 10 days, then what will be Raman's share?

  1. Rs. 2322.37

  2. Rs. 2412.21

  3. Rs. 2331.45

  4. Rs. 2341.14

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

Rates: Sonia = 1/18, Raman = 1/54, Parmit = 1/108. In 10 days, Sonia does 10/18 work. Remaining work = 1 - 10/18 = 8/18 = 4/9. Raman and Parmit finish this together. Their combined rate = 1/54 + 1/108 = 3/108 = 1/36. Time taken = (4/9) / (1/36) = 16 days. Total work done by Raman = 16/54 = 8/27. Share = (8/27) * 7838 = 2322.37.