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The time taken to do a piece of work is inversely proport...

The time taken to do a piece of work is inversely proportional to the number of men employed. if it takes 45 men to do a piece of work in 5 days, how long will it take 25 men?

A.

15 days

B.

12 days

C.

5 days

D.

9 days

Correct answer is D

The time (t) to do the work is inversely proportional to the number of workers (n).

\(\implies t \propto \frac{1}{n}\)

\(t = \frac{k}{n}\)

\(5 = \frac{k}{45} \implies k = 45 \times 5 = 225\)

\(\therefore t = \frac{225}{n}\)

For 25 men, \(t = \frac{225}{25} = 9\)

\(\therefore\) 25 men will do the work in 9 days.