Acar covered a certain distance at a speed of 24 mph. while returning, the car covered the same distance at a speed of 16 mph. what was the average speed of the car for the entire journey?

Since the distances were the same you can find the average speed directly by adding the speeds then dividing by 2. No need to weight anything.

If we’re considering speed regardless of direction, the average speed is:

(24 + 16) / 2 = 40 / 2 = 20mph

However if direction matters, then one number has to be negative since the directions are opposite:

(24 - 16) / 2 = 8 / 2 = 4mph (in the positive direction)

Depending on the context, either of these could be your answer.