Question

P q and r can do apiece of work in 30 , 24 nd 40 days respectively. They start work together but r leaves 4 days before the completion of work . In how many days is the work done?

Answer 1

Hey mate here is your answer:
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Work done by R in 1 days:
work done by (p+q+r) in one day
= 1/30+1/24+1/40( reciprocaled)

Work done by R in 4 days:
work done by (p+q+r) in four days
= 4/30+4/24+4/40(reciprocaled and added 4 bcz 4 days)
=12+16+20/480(l.c.m)
= 48/480
= 1/10 work was done by p, q,r in four days !

Work left:
= 1-1/10
=9/10

Remaning Work to be done by p,q,r in how many days:
= work done by p in one day = 1/30
work done by q in one day = 1/24
so , A.T.Q , they both worked together then it will be as follows::::
1/30+1/24/9/10 {9/10 is the remaining work}
= (4+3/120)/9/10{ l.c.m}
= 7/120/9/10( four terms can also be written as follows:)
= 7/120*10/9
= 25/36
= 36/25( reciprocal )
= 11
1 _. { Mixed fraction}

36