The speed of the car was 45 mph. A driver noticed that while moving with this speed it took him 40 seconds to cross a bridge. On the way back crossing the same bridge, it took him 30 seconds. What was the speed of the car on the way back?
Accepted Solution
A:
distance = speed*time
Each time the car travels the same distance across the bridge.
By setting the distances equal you get the following equation:
[tex]30x = 40*45 \\ \\ x = \frac{40*45}{30} = 60[/tex]