Arshi can do a piece of work in 30 days, while Ahan can complete it in 20 days. Both together labour for 4 days and afterwards Ahan leaves. How long will Arshi take to complete the remaining work?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 20 days
Given:
Arshi can do a piece of work in 30 days
Ahan can complete it in 20 days.
Both together labour for 4 days and afterwards Ahan leaves
Calculations:
Total work (LCM of 30 and 20) = 60 units
Efficiency of Arshi = 60/30 = 2 units
Efficiency of Ahan = 60/20 = 3 units
Total efficiency = 2 + 3 = 5 units
Work done in 4 days = 5 × 4 = 20 units
Remaining work = 60 - 20 = 40 units
Remaining work is completed by arshi = 40/2 = 20 days