N and K together can complete a work in 240 days, K and G together can complete the same work in 72 days and N and G together can complete the same work in 80 days. In how many days K alone can complete the same work?
Answer & explanation
Correct answer: option 3
N + K = 240 days, K + G = 72 days, N + G = 80 days,
⇒ Adding all the efficiencies,
⇒ 2(N + K + G) = 22
⇒ N + K+ G = 11,
Now,
⇒ N + 10 = 11,
⇒ N = 1,
⇒ N + K = 3,
⇒ 1 + K = 3,
⇒ K = 2,
Therefore time required by K to complete total work = \(\frac{720}{2}\) = 360 days, ..(\(\frac{Work}{Efficiency}\) = Time)