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

Forty men can finish a piece of work in 40 days. Assume that each worker is working with equal efficiency Column A Column B Total time required for the whole work to be completed if 5 men leave after every tenth day. 56 days Compare the two quantities to decide whether

  1. the quantity in Column A is greater

  2. the quantity in Column B is greater

  3. the two quantities are equal

  4. the relationship cannot be determined from the information given
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Days 1-10: 40 men * 10 days = 400 units. Days 11-20: 35 men * 10 days = 350 units. Days 21-30: 30 men * 10 days = 300 units. Days 31-40: 25 men * 10 days = 250 units. Days 41-50: 20 men * 10 days = 200 units. Total units = 1600. Remaining work = 1600 - 1500 = 100. Days 51+: 15 men. 100/15 = 6.66 days. Total time = 50 + 6.66 = 56.66 days. Since 56.66 > 56, Column A is greater.

Multiple choice

Ten men could finish a job in 40 days, in normal working hours, but they increased their working hours by 25% a few days after starting the work, so as to complete the work in 34 days. How many days after the start of the work did they increase the working hours?

  1. 4

  2. 6

  3. 8

  4. 10

  5. 12
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let d be the days worked at normal hours. Total work is 10 * 40 = 400 man-days. Work done in d days is 10d. Remaining work (400 - 10d) is done in (34 - d) days by 10 men working at 1.25 efficiency. So, 10d + (34 - d) * 10 * 1.25 = 400. Solving gives 10d + 425 - 12.5d = 400, so 2.5d = 25, d = 10.

Multiple choice

3 men finish painting a wall in 8 days. Four boys do the same job in 7 days. In how many days will 2 men and 2 boys working together paint two such walls of the same size?

  1. 6 6/13 days

  2. 3 3/13 days

  3. 9 2/5 days

  4. 12 12/13 days
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

3M = 8 days -> 1M = 24 days. 4B = 7 days -> 1B = 28 days. Work rate of 2M + 2B = 2/24 + 2/28 = 1/12 + 1/14 = (7+6)/84 = 13/84. Time for 1 wall = 84/13 days. Time for 2 walls = 168/13 = 12 12/13 days.

Multiple choice

A can do a piece of work in 15 days while B can do it in 20 days. They work together for 5 days and remaining work is completed by C in 10 days. If the total amount received for the whole work is $6000, how should the money be divided among them?
  1. $2000, $1500, $2500
  2. $1800, $2800, $800
  3. $2000, $1400, $1000
  4. $900, $1600, $1400
  5. $1500, $2000, $2500
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A's rate is 1/15, B's is 1/20. Together they do (1/15 + 1/20) = 7/60 per day. In 5 days, they do 35/60 = 7/12 of the work. C does the remaining 5/12 in 10 days, so C's rate is (5/12)/10 = 1/24. The ratio of work done is A: 5/15 = 1/3, B: 5/20 = 1/4, C: 5/12. Ratio is 4:3:5. Dividing 6000 in this ratio: A = 2000, B = 1500, C = 2500.