Question

30 men can finish a piece of work in 28 days. How many days will be taken by 21 men to finish.

Answer 1

More the no. of men, lesser the days. So, it is an inverse proportion. 

Let the required time be x days. 

⇒ 30 × 28 = 21 × x

⇒ x = \(\frac{30\,\times\,28}{21}\) = 40 days