A alone can complete a work in 18 days. A and B together can complete the work in 10(2/7) days. A and C together can complete the work in 12 days. At what time B and C together can complete 83(1/3)%of work?
a) 18 days
b) 12 days
c) 15 days
d) 20 days
e) 24 days
Sol:
The time taken by B alone to complete the work
= (7/72) – (1/18) = (7 – 4)/72 = 1/24
= 24 days
The time taken by C alone to complete the work
=(1/12) – (1/18) = (3 – 2)/36 = 1/36
= 36 days
Work done by B and C together in 1 day = (1/24)
+ (1/36) = 5/72
So, time taken by B and C together to complete
83(1/3)%of work:
(72/5) * (250/300) = 12 days
