A and B complete a work in 10 days, B and C complete the same in 15 days, C and A in 20 days. How ma

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28 Aug 2012 work

A and B complete a work in 10 days, B and C complete the same in 15 days, C and A in 20 days. How many days are required to do the same work if A, B, C work together.

OPtion

1) 90/13
2) 80/13
3) 45/13
4) 30/13
5) 60/13
6) 120/13
7) 20/13
8) 150/13
9) 200/13
10) none of these

Solution

one day work of all the 3 pairs are 1/10, 1/15, 1/20 respectively
so one day work of A, B, C will be 1/2[(1/10)+(1/15)+(1/20)] = 13/120
so days required = 120/13

Correct Option: 6 Best Solution (0)