(A) 30
(B) 40
(C) 50
(D) 60
Correct Option is: C
Work done by P,Q & R in 8 days = 1/20 * 8
=2/5
Remaining work = (1 – 2/5) = 3/5
Now 3/5 work is done by Q & R in 20 days
Whole work will be done by Q & R in(20*5/3) =100/3 days
(P+Q+R)’s 1 day work = 1/20
(Q+R)’s 1 day work = 3/100
P’s 1 day work =(P+Q+R)’s 1 day work – (Q+R)’s 1 day work
=1/20 – 3/100
=5-3/100
=2/100 =1/50
P alone could complete the work in 50 days.