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

8 men and 4 women together can complete a piece of work in 4 days. Work done by a man in one day is double the work done by a woman in one day. If 8 men and 4 women started working, and after 2 days, 4 men left and 4 new women joined, then in how many more days will the work be completed?

  1. 2.5 days

  2. 7.5 days

  3. 6 days

  4. 4 days

  5. 9 days
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

8M + 4W = 4 days. 1M = 2W, so 8M + 4W = 16W + 4W = 20W. Total work = 20W * 4 = 80W-days. After 2 days, 40W-days done. Remaining = 40W-days. New group: 4M + 8W = 8W + 8W = 16W. Time = 40W / 16W = 2.5 days.

Multiple choice

Directions: Solve the following question and mark the best possible option. Persons A and B can complete a job in 90 days and 150 days, respectively. A and B together work on day 1. On day 2, A and B are joined by two new persons with the equal efficiency. On the day 3, they are joined by two persons of equal efficiency. In the same pattern, every day, two new persons with the same respective efficiency join the work. How many days (approximately) are required to complete the job together?

  1. 20 days

  2. 5 days

  3. 10 days

  4. 18 days

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

A's rate = 1/90, B's rate = 1/150. Day 1: (1/90 + 1/150) = 8/450 = 4/225. Day 2: 2(A+B) = 8/225. Day 3: 3(A+B) = 12/225. Sum after n days = (A+B) * (1+2+...+n) = (4/225) * n(n+1)/2 = 1. n(n+1) = 225/2 = 112.5. n is approx 10.

Multiple choice

Harish, Mahesh and Atul can make furniture in 36 days, 12 days and 24 days, respectively. If Mahesh works for first two days and after that three of them work together to make furniture, how much time will they take?

  1. 9.5 days

  2. 5 days

  3. 10 days

  4. 7.45 days

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

Harish=1/36, Mahesh=1/12, Atul=1/24. Mahesh works 2 days: 2/12 = 1/6. Remaining = 5/6. Together: 1/36+1/12+1/24 = (2+6+3)/72 = 11/72. Time = (5/6) / (11/72) = (5/6) * (72/11) = 60/11 = 5.45 days. Total time = 2 + 5.45 = 7.45 days.

Multiple choice

Atul can complete an assignment in 12 days, Harman in 8 days and Chetan in 10 days. Harman and Chetan started the assignment, but were asked to stop after 3 days. In how many days would Atul complete the assignment now?

  1. 3.9 days

  2. 4 days

  3. 4.5 days

  4. 7.3 days

  5. 8.2 days
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Harman and Chetan's combined rate is 1/8 + 1/10 = 5/40 + 4/40 = 9/40 per day. In 3 days, they complete 3 * 9/40 = 27/40 of the work. Remaining work = 1 - 27/40 = 13/40. Atul's rate is 1/12. Time for Atul = (13/40) / (1/12) = (13 * 12) / 40 = 156 / 40 = 3.9 days.

Multiple choice

The ratio of the efficiencies of A, B and C is 7 : 5 : 4. By working together, they can finish a work in 35 days. A and B work together for 28 days. The remaining work completed (in days) by C alone will be

  1. 56

  2. 63

  3. 49

  4. 60
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Total work = (7+5+4) * 35 = 16 * 35 = 560 units. A+B work for 28 days: (7+5) * 28 = 12 * 28 = 336 units. Remaining work = 560 - 336 = 224 units. C's efficiency = 4. Days for C = 224 / 4 = 56.

Multiple choice

P does 40% of a piece of work in 10 days. He then calls Q and they together finish the remaining work in 9 days. How long will Q alone take to complete the whole work?

  1. 35.5 days

  2. 25 days

  3. 29 days

  4. 37.5 days

  5. None of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

P does 40% in 10 days, so P's rate is 4% per day. Remaining work is 60%. P and Q finish 60% in 9 days, so their combined rate is 60/9 = 6.66% per day. Q's rate = 6.66 - 4 = 2.66% per day. Time for Q = 100 / 2.66 = 37.5 days.

Multiple choice

A alone can do a piece of work in 8 days, B alone can do the same in 10 days, and C alone can do the same in 12 days. If all three of them do this piece of work together and they are paid Rs. 7400 in return, then what will be the share (in Rs.) of B?

  1. 2600

  2. 3000

  3. 2400

  4. 2000
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Work rates: A=1/8, B=1/10, C=1/12. Ratio of work done = 1/8 : 1/10 : 1/12. Multiply by 120: 15 : 12 : 10. Total parts = 37. Share of B = (12/37) * 7400 = 12 * 200 = 2400.