Question

71. Twelve men can complete a work in 8 days. Three
days after they started the work and 3 more men
joined. In how many days will all of them together
complete the remaining work?
a) 2 6) 4 c) 5 d) 6​

Answer 1

Answer:

(b) 4 days.

Step-by-step explanation:

12 men's one day work = 1/8

So, 1 man's one day work = 1/(8*12) = 1/96

So, 12 men's 3 day's work = (12*3)/96 = 36/96

Work left = 1 - 36/96 = 60/96.

Now, use unitary method:

12 men can do 1 work in 8 days

So, 1 man can do 1 work = 12*8 = 96 days

So, 15 men can do (60/96) work = (96/15)*(60/96) = 4 days.