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

Directions: Compare the two quantities in A and B. Quantity A Quantity B Number of people required to complete a task in 6 days if 30 people can do it in 10 days Number of people required to complete a work in 5 days if 20 people can do it in 8 days

  1. Quantity A is greater than quantity B.

  2. Quantity B is greater than quantity A.

  3. Both quantities are equal.

  4. The relationship between the quantities cannot be determined.

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

Quantity A: 30 people * 10 days = 300 man-days. Required people = 300 / 6 = 50. Quantity B: 20 people * 8 days = 160 man-days. Required people = 160 / 5 = 32. Since 50 > 32, Quantity A is greater.

Multiple choice

Adam, Brandon and Charlie can do a piece of work in 20, 30 and 40 days, respectively. They started working together, but from the first day itself, Adam came to work on alternate days. In how many days would the work be completed?

  1. 8

  2. 12

  3. 15

  4. 16

  5. 20
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Work rates: A=1/20, B=1/30, C=1/40. LCM=120. A=6, B=4, C=3 units/day. Day 1 (A,B,C): 6+4+3=13. Day 2 (B,C): 4+3=7. Cycle of 2 days = 20 units. 120/20 = 6 cycles. Total days = 6 * 2 = 12.

Multiple choice

A and B can do a piece of work in 12 days. If the time taken by A is 3 2 times the time taken by B to do the work individually, then find the number of days in which A can do the work individually.

  1. 15 days

  2. 20 days

  3. 25 days

  4. 30 days

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

Interpreting the stated time ratio as A's time being 3/2 times B's time, let B take t days and A take 3t/2 days. Their combined rate is 1/t + 2/(3t) = 1/12, giving t = 20 and A's time as 30 days.

Multiple choice

A can complete a piece of work in 30 days and B can do the same in 60 days. C is 50% more efficient than A. Find the number of days in which the work will be completed if A, B and C work together.

  1. 8 days

  2. 10 days

  3. 12 days

  4. 15 days

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

A = 1/30 work/day. B = 1/60 work/day. C is 50% more efficient than A, so C = 1.5 * (1/30) = 1/20 work/day. Combined rate = 1/30 + 1/60 + 1/20 = (2+1+3)/60 = 6/60 = 1/10. Time = 10 days.

Multiple choice

Directions: In this problem, a question is given followed by three statements, numbered I, II and III. Read the statements carefully and decide which of them is/are sufficient to answer the question. In how many days can 5 men complete a task? I. Two men, three women and five children together can complete the task in 10 days. II. Three men can complete one-fourth of the task in 10 days. III. Nine women can complete the task in 18 days.

  1. Only II and III

  2. Only I and III

  3. Only I and II

  4. Only II

  5. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Statement II says 3 men complete 1/4 of the task in 10 days, so 3 men complete the task in 40 days. Thus, 1 man completes the task in 120 days, and 5 men complete it in 120/5 = 24 days. Only statement II is sufficient.

Multiple choice

If A takes half as long to do a piece of work as B takes, and if C takes the time same as A and B together, and if all three, working together take 7 days, then how long would each take separately?

  1. 21 days, 21 days, 14 days

  2. 21 days, 42 days, 14 days

  3. 21 days, 21 days, 21 days

  4. 7 days, 14 days, 28 days
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let A's rate be 2x, B's rate be x, and C's rate be 3x. Combined rate is 6x. Since they take 7 days together, 6x * 7 = 1 (total work), so x = 1/42. A takes 21 days, B takes 42 days, and C takes 14 days.