A is 50% as efficient as B. C does half the work done by A and B together. If C alone does the work in 40 days, then in how many days will A, B and C together finish the work?
Problem:
Couldn't relate work and time from data given for C to A and B.
My attempt:
Let B take 'b' days to complete a work W. Then A will take 2*b days to complete the same work (w).
Given that c's work = (W(A)+W(B))/2 = 0.75*W
C can do W in 40 days. Hence 0.75W can be done by C in 30 days.
After this, how do i relate the work done by A and B in 1 day to C's 1 day work so that i can find the combined 1 day's work for all three?
Best Answer
Hint: if B takes $b$ days to finish, he does $\frac 1b$ per day. Then A does $\frac 1{2b}$ per day. Then how much of the task does C do per day in terms of $b$. You are given that C does $\frac 1{40}$ per day, so....