30 men can complete a piece of work in 12 days. 30 men started working, after four days 10 men left the work. How many more days will the remaining men now take to complete the remaining work?
15 days
19 days
12 days
11 days
14 days
Solution
Time taken by 20 men to complete the work
$= 2 0\times D = 30 \times 12$
D = 18 days
Work done by 30 men in 4 days $= \dfrac {1}{12} \times = \dfrac {1}{3}$
Work left $= \dfrac {2}{3}$
time taken by 20 men to complete it $= \dfrac {2}{3 \times 1} \times 18$ = 12 more days