A and B together can do a piece of work in 20 days. B and C can do it in 15 days while A and C take 12 days to do the same piece of work .
a. In how many days will A,B and C finish it working together?
b. In how many days will it one of them finish it working alone ?
Answers
Answer:
Let total work = LCM(20,15,12) = 60 units
A + B complete 3 units in 1 day
B + C complete 4 units in 1 day
C + A complete 5 units in 1 day
Adding :
=> A+B+C complete 12/2 = 6 units in 1 day
=> C can finish 6–3 = 3 units in 1 day
=> B can finish 6–5 = 1 units in 1 day
=> A can finish 6–4 = 2 units in 1 day
So A, B & C can finish the work alone in 30, 60 and 20 days respectively.
:-)
Answer:
Let total work = LCM(20,15,12) = 60 units
A + B complete 3 units in 1 day
B + C complete 4 units in 1 day
C + A complete 5 units in 1 day
Adding :
=> A+B+C complete 12/2 = 6 units in 1 day
=> C can finish 6–3 = 3 units in 1 day
=> B can finish 6–5 = 1 units in 1 day
=> A can finish 6–4 = 2 units in 1 day
So A, B & C can finish the work alone in 30, 60 and 20 days respectively.
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