Correct Answer - Option 1 : 42 km/hr
Given:
Speed of the car for a certain distance = 70 km/hr
Speed of the car for coming back = 30 km/hr
Formula Used:
Average speed = 2xy/(x+y)
x and y are the speed of the car
Calculation:
The average speed of the car = 2xy/(x+y)
2xy/(x+y) = (2 × 70 × 30)/(70 + 30) ⇒ 42 km/hr
∴ The average speed for total journey is 42 km/hr
