Ravi can complete a task in 6 days and Mohan can complete the same task in 9 days. In how many days can Ravi and Mohan together complete the same task?

$3\frac{3}{5}$ days

Ravi = 6 days, Mohan = 9 days,

⇒ Time required by Ravi and Mohan to complete the work together = \(\frac{18}{3+2}\) =  \(\frac{18}{5}\) =  \( { 3}_{5 }^{3 } \) days,    ..(\(\frac{Work}{Efficiency}\) = Time)