Practicing Success
Zen can finish a work in 20 days. He start doing the work and after 6 days John joined him. If both of them together completed the remaining work in 7 days, then in how many days can John alone finish 80% of the same work? |
20 days 16 days 15 days 10 days |
16 days |
Let total work = 20 Zen can do it in 20 days, therefore, Efficiency of Zen = 1 w/d Work done by Zen in 6 days = 6 Remaining work = 20 - 6 = 14 Remaining work done by Zen + John in 7 days Efficiency of Zen + John = \(\frac{14}{7}\) = 2 w/d Efficiency of John = 2 - 1 = 1 John will do 80% work in = \(\frac{20\;×\;4}{5\;×\;1}\) = 16 days |