Question

A certain piece of work can be completed by 108 men in 30 days.After 5 days , 8 men leave the job but 35 more men are employed.How much longer will the job take to be completed?

Answer 1

But in 5 days, 108 men would have already completed $\left(\frac{5}{30}\right)=\left(\frac{1}{6}\right)th$ of the work. So, remaining work is $\left(\frac{5}{6}\right)$.
Time needed by 135 men to finish $\left(\frac{5}{6}\right)th$ of the work $=\left(\frac{5}{6}\right)\times 24=20days$