Time and Work Practice Questions

5 questions per page • Detailed step-by-step solutions

Question 1
Medium
A contract is to be completed in 56 days and 104 men were set to work, each working 8 hours a day. After 30 days, 2/5 of the work is finished. How many additional men may be employed so that work may be completed on time?
A 80
B 56
C 104
D 76
Correct Answer: D

Explanation:

104 men × 30 days did 2/5 of the work. Remaining 3/5 in 26 days: M = 104 × 30 × (3/5)/(2/5)/26 = 104 × 30 × 1.5/26 = 180 men. Additional men = 180 − 104 = 76.
Question 2
Easy
A can complete a piece of work in 12 days. B is 60% more efficient than A. The number of days, that B will take to complete the same work is
A 7 days
B 7 1/2 days
C 6 1/2 days
D 8 days
Correct Answer: B

Explanation:

B's efficiency = 1.6 × A → B's time = 12/1.6 = 7.5 days.
Question 3
Medium
If 72 men can build a wall of 280 m length in 21 days, how many men could take 18 days to build a similar type of wall of length 100 m ?
A 25
B 30
C 36
D 35
Correct Answer: B

Explanation:

Men = 72 × 21 × 100/(280 × 18) = 151200/5040 = 30.
Question 4
Medium
45 men can complete a piece of work in 16 days. Four days they started working , 36 more men joined them. How many days will they take to complete the remaining work ?
A 8 days
B 6 days
C 6 2/3 days
D 7 days
Correct Answer: C

Explanation:

45 × 16 = 720. After 4 days, 540 remain. 81 men → 540/81 = 6 2/3 days.
Question 5
Easy
15 person can complete a work in 60 days. If the number of persons is increased by 5, how many days earlier will the work get completed?
A 15 days
B 10 days
C 12 days
D 20 days
Correct Answer: A

Explanation:

15 × 60 = 900 person-days. 20 persons need 900/20 = 45 days → 60 − 45 = 15 days earlier.