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

Three workers together can do a job in 12 days. Two of them work faster than the third worker. Each of the two faster workers works twice as fast as the third worker. How long will it take for one of the faster workers to do the job all by himself?

  1. 18 days

  2. 36 days

  3. 30 days

  4. 24 days

  5. 21 days
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The range of a data set is the difference between the maximum and minimum values. The number of chocolate bars ranges from 0 to 5. Range = 5 - 0 = 5.

Multiple choice

A piece of work can be completed in 2 days by 4 men. 4 women can complete the same piece of work in 4 days, whereas, 5 children can complete the same piece of work in 4 days. If 2 men, 4 women and 10 children work together, in how many days can the work be completed?

  1. 1 day

  2. 3 days

  3. 2 days

  4. 4 days

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

Work = 4 men * 2 days = 8 man-days. 4 women * 4 days = 16 woman-days. 5 children * 4 days = 20 child-days. 1 man = 1/8 work/day, 1 woman = 1/16 work/day, 1 child = 1/20 work/day. 2 men + 4 women + 10 children = 2/8 + 4/16 + 10/20 = 1/4 + 1/4 + 1/2 = 1 work/day. Time = 1/1 = 1 day.

Multiple choice

Horrik and Ecbert can together plough a field in 60 days. They worked together for 40 days and then, Ecbert left the task. After another 40 days, Horrik completed the remaining task. Horrik alone complete the task in how many days?

  1. 100 days

  2. 96 days

  3. 120 days

  4. 108 days

  5. 80 days
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let H and E be the work rates. (H+E)*60 = 1. (H+E)*40 + H*40 = 1. 40H + 40E + 40H = 1 -> 80H + 40E = 1. Since E = 1/60 - H, 80H + 40(1/60 - H) = 1. 80H + 2/3 - 40H = 1. 40H = 1/3. H = 1/120. Horrik takes 120 days.

Multiple choice

A project was given to some students to be finished in 100 days. But due to some circumstances, 10 students could not take part in the completion of the project and it took 10 more days to get completed. How many students were assigned to complete the project initially?

  1. 110

  2. 80

  3. 340

  4. 220

  5. 155
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let x be the initial number of students. Total work = 100x. With (x-10) students, it takes 110 days: 110(x-10) = 100x. 110x - 1100 = 100x, so 10x = 1100, x = 110.

Multiple choice

X, Y and Z individually do a job in 24, 30 and 40 days, respectively. X works alone for the 1st day, then Y works alone for next 2 days and then Z works alone for next 3 days. The same pattern is repeated. In how many days will the job be finished?

  1. 32

  2. 32.7

  3. 64.5

  4. 32.25

  5. 30
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Rates: X=1/24, Y=1/30, Z=1/40. Work per cycle (6 days): 1*(1/24) + 2*(1/30) + 3*(1/40) = 1/24 + 1/15 + 3/40 = (5+8+9)/120 = 22/120 = 11/60. In 5 cycles (30 days), work = 55/60. Remaining 5/60 = 1/12. Day 31: X does 1/24. Day 32: Y does 1/30. Remaining work = 1/12 - 1/24 - 1/30 = 1/24 - 1/30 = 1/120. Day 33: Z does 1/40. Time = 32 + (1/120)/(1/40) = 32 + 1/3 = 32.33. The closest option is 32.25.