Ravi and Mohan together can complete a task in 3 days. Ravi alone can complete can complete the same task in 7 days. How many days will Mohan alone take to complete the same task?
Answer & explanation
Correct answer: option 1
Ravi(R) + Mohan(M) = 3 days,
Ravi(R) = 7 days,
⇒ R + M = 7, (Efficiency)
⇒ 3 + M = 7,
⇒ M = 4,
⇒ Time required by Mohan to complete the total work alone = \(\frac{21}{4}\) = \( {5 }_{4 }^{1 } \) days, ..(\(\frac{Work}{Efficiency}\) = Time)