Correct Answer - Option 3 : Rs. 5340

**Given:**

C.P of 35 watches = Rs. 4200

Profit on 25 watches = 30%

Profit on 10 watches = 20%

**Formula used:**

Profit % = (Profit)/(C.P) × 100

S.P = [(100 + P%) × C.P]/100

**Calculation:**

Cost price of 1 items = Rs. 4200/35 = Rs. 120

S.P of 25 items = (130/100) × 120 = Rs. 156

⇒ S.P of 25 items = 25 × 156 = Rs. 3900

S.P of 10 items = (120/100) × 120 = Rs. 144

⇒ S.P of 10 items = 10 × 144 = Rs. 1440

Total S.P of 35 items = Rs. (2340 + 1440) = Rs. 5340

**∴ Total S.P of 35 watches is Rs. 5340.**