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 are skilled labourers, each capable of completing a certain task individually within distinct time frames of 12, 30, and 60 days, respectively. They embarked on a collaborative project, initially working together. However, B chose to depart the project after contributing his expertise for a period of 6 days before completion of the project, while C chose to depart 8 days before completion of the project, then what is the total precise duration required to complete the task?

  1. 12 days

  2. 10 days

  3. 9 days

  4. 8 days
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let total days be T. A works for T days, B for T-6, C for T-8. (T/12) + (T-6)/30 + (T-8)/60 = 1. Multiply by 60: 5T + 2(T-6) + (T-8) = 60. 5T + 2T - 12 + T - 8 = 60. 8T = 80. T = 10.

Multiple choice

DIRECTION for the question: Solve the following question and mark the best possible option. Sixteen men can complete a work in twelve days. Twenty-four children can complete the same work in eighteen days. Twelve men and eight children started working and after eight days three more children joined them. How many days will they now take to complete the remaining work?

  1. 8

  2. 2

  3. 5

  4. 4

  5. 7
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

16M = 12 days -> 1M = 192 days. 24C = 18 days -> 1C = 432 days. 12M + 8C rate = 12/192 + 8/432 = 1/16 + 1/54 = 35/432. Work done in 8 days = 8 * 35/432 = 35/54. Remaining = 19/54. New rate (12M + 11C) = 12/192 + 11/432 = 1/16 + 11/432 = 38/432 = 19/216. Time = (19/54) / (19/216) = 216/54 = 4 days.

Multiple choice

DIRECTION for the question: Solve the following question and mark the best possible option. X and Y can do a piece of work in 20 days and 12 days respectively. X started the work alone and then, after 4 days, Y joined him till the completion of the work. How long did the work last?

  1. 23

  2. 12

  3. 5

  4. 10

  5. 6
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

X does 1/20 of work per day, Y does 1/12. In 4 days, X does 4/20 = 1/5 of work. Remaining work = 4/5. Together, they do (1/20 + 1/12) = (3+5)/60 = 8/60 = 2/15 per day. Time for remaining work = (4/5) / (2/15) = (4/5) * (15/2) = 6 days. Total time = 4 + 6 = 10 days.

Multiple choice

Two men undertook to do a piece of work for Rs. 6000. One alone could do it in 15 days and the other can do it in 12 days, while with the assistance of a boy, work gets completed in 5 days. What is the ratio of there work done?

  1. 2:6:7

  2. 4: 5: 3

  3. 4:8:9

  4. 3:2:8

  5. 9:7:5
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The work rates are 1/15, 1/12, and 1/5 per day. The boy's rate is 1/5 - (1/15 + 1/12) = 1/5 - 9/60 = 1/5 - 3/20 = 1/20. The ratio of their work is 1/15 : 1/12 : 1/20, which simplifies to 4:5:3.