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**