Question

A certain distance was covered by a car at a speed of 60 km per hour and comes back at the speed of 36 km per hour . What is the average speed of the car ?

• A. 30 Km/hr
• B. 40 Km/hr
• C. 45 Km/hr
• D. 48 Km/hr

Answer 1

Answer:

C. 45 Km/hr

The average speed of the car is 45 km/h.

When an object covers the same distance at two different speeds,

$\text{Average Speed} = \frac{2 \times x \times y}{x + y}$

Where:

• $x$ = Speed while going = 60 km/h

• $y$ = Speed while returning = 36 km/h

Calculation:
$\text{Average Speed} = \frac{2 \times 60 \times 36}{60 + 36}$

$\text{Average Speed} = \frac{4320}{96}$

$\text{Average Speed} = \mathbf{45\text{ km/h}}$