The time taken to do a piece of work is inversely proportional to the number of men employed. If it takes 30 men to do a piece of work in 6 days, how many men are required to do the work in 4 days?
A
20
B
35
C
45
D
60
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
t = time taken and N = number of men
t ∝ 1/N
t = K/N
K = Nt
K = 30 * 6
K = 180
∴t = 180/N
4 = 180/N
4N = 180
N = 180/4
45 men
Source: Myschool Past Questions Archive (Record #8227)