Correct Answer - Option 2 : 120 days
Given
Chin and Chan together can complete a piece of work in 40 days while Chin alone can complete the same work in 60 days
Concept used
Work efficiency
Calculation
Chin and Chan do work together = 40 days
⇒ 1 day work of Chin and Chan = 1/40
⇒ Chin can do same work = 60 days
⇒ 1 day work of Chin = 1/60
According to question
⇒ 1 day work of Chan = 1/40 - 1/60
⇒ (3 - 2)/120 = 1/ 120
∴ Chan can do the same work along in 120 days