Question

A,b,c can separately do a work in 30,20,15 days respectively.a does a piece of work on the first day, b does on second day and c does on third day.again on the 4th day a does a piece of work and in the same way they work till their completion of the work. in how many days does the work gets completed

Answer 1

let the total work be 60

a completes in 30 days so , a daily work 2

b completes in 20 days so , a daily work 3

c completes in 15 days so , a daily work 4


when a starts first day 2 work is done
next day b works and more 3 work is done
third day when c works 4 more work is done


so total 9 work in 3 days

so , 54 work in 18 days

now remaining 6 work first in 19th day a completes 2 work

on 20 th day b completes 3 work

and on 21 th day remaining 1 work is done by c in 1/4 of day


so total 20 and 1/4 days requires