Correct Answer - Option 2 : 35.88 km/h

**Given:**

Travel 400 km in 10 hours.

Travel 210 km in 7 hours.

**Formula used:**

Average speed = Total distance/Total time taken

**Calculation:**

Total distance = (400 + 210) km

⇒ 610 km

Total time = (10 + 7) hours

⇒ 17 hours

Average speed = 610/17 km/hr

⇒ 35.88 km/h

**∴ The average speed is 35.88 km/hr**