Question bc2c7

Feb 26, 2018

30 days

Explanation:

Total work to be done is:
(30 men)(35 days) = 1050 man-days

After 10 days of work with 30 men:
$30$ men (10 days) = 300# man-days are complete

This leaves $1050 - 300 = 750$ man-days left to finish

Now with only 25 men:
$750$ man-days$/ 25$ men$= 30$ days

So it will take the remaining workers 30 days to finish the job.

Feb 26, 2018

The remaining men will finish the job in 30 days.

Explanation:

The whole job can be unit 1, which can be done by 30 men in 35 days. So a man one day can finish $\frac{1}{35 \cdot 30}$ job.
After 10 days, the remaining job is $1 - \frac{10}{35} = \frac{5}{7}$.
So every day the remaining $30 - 5 = 25$ men can finish the job $25 \cdot \frac{1}{35 \cdot 30} = \frac{1}{42}$; they still need $\frac{5}{7} / \left(\frac{1}{42}\right) = 30$ days to finish the job.

Feb 26, 2018

30 days

Explanation:

$30 \cdot 35 = 1050$ => man days required to do the job

$30 \cdot 10 = 300$ => man days completed in 10 days

$1050 - 300 = 750$ => man days of work remaining

25 men to do 750 man days:

$\frac{750}{25} = 30$ => days for 25 men to complete the job