Three friends A, B and C worked together to complete the work. A takes 4 days more to complete same work done by A and B. Work done by C in 4 days is equal to the work done by A in one day. Work done by B in 3 days is equal to the work done by C in 8 days. Find the time in which work will be completed if all three worked together.
Three friends A, B and C worked together to complete the work. A takes 4 days more to complete same work done by A and B. Work done by C in 4 days is equal to the work done by A in one day. Work done by B in 3 days is equal to the work done by C in 8 days. Find the time in which work will be completed if all three worked together. Correct Answer 120/23 days
Calculation:
Let number of hours taken by A, B and C to complete the work be a, b and c respectively.
⇒ 3/b = 8/c
⇒ 3c = 8b
⇒ 4/c = 1/a
⇒ c = 4a
⇒ b = 3a/2
⇒ 1/a + 1/b = 1/(a - 4)
⇒ 1/a + 2/3a = 1/(a - 4)
⇒ a = 10
⇒ b = 15
⇒c = 40
(A + B + C)'s 1 hours work = 1/10 + 1/15 + 1/40 = 23/120
∴ Working together, A, B and C can complete the work in 120/23 days.
Important Points
Work done in a hours by person = a × persons 1 hour's work