Answer:
Option B
Explanation:
20 men, 20 days, $\frac{1}{3}$ work = $\frac{1}{20}\times\frac{1}{20}\times\frac{1}{3}$ $=\frac{1}{1200}$ the amount of the work one man does in each day.
To finish $\frac{2}{3}$ the work in 25 days is $\frac{2}{3}\times\frac{1}{25}$ $=\frac{2}{75}$ work needs to be done each day.
$\frac{n}{1200}=\frac{2}{75}$
$75n=2400$
$n=\frac{2400}{75}$ = 32 men.
Since you already have 20 men, you need to hire $12$ more to finish the job on time.
