A can do 60% of a work in 18 days, while B can do 40% of the same work in 10 days. Both work together for 10 days only. C completed the remaining work in 4 days. In how many days will C complete the same work?

15

A = 60% of W = 18 days = 30 days,

B = 40% of W = 10 days = 25 days,

⇒ A + B worked for 10 days = (5 + 6) x 10 = 11 x 10 = 110 units,   ..(Efficiency × Days = Total work)

⇒ Remaining work = 150 - 110 = 40 units,

⇒ C completed the remaining work in 4 days = \(\frac{40}{C}\) = 4 days,

⇒ C = 10,   (Efficiency)

⇒ Time required for C to complete total work = \(\frac{150}{10}\) = 15 days  ..(\(\frac{Work}{Efficiency}\) = Time)