40 workers can complete work in 14 days Eight days after they started working 20 more men joined the...........

Quantitative Aptitude (CDS) Time and work

40 workers can complete work in 14 days. Eight days after they started working, 20 more men joined them. How many days will they now take to complete the remaining work?

6 days

2 days

7 days

4 days

Explanation:

(40 ×14) workers can complete the work in 1 day.
1 worker's 1 day's work = 1/560.
40 worker's 8 day's work = ( 1/14 × 8 ) = 4/7.
Remaining work = 1- (4/7) = 3/7
60 worker's 1 day's work = 60/560 = 3/28
Now, 3/28 work is done by them in 1 day.
3/7 work is done by them in (28/3) × (3/7) = 4 days