A vehicle covers certain distance at constant speed of `20 km h^(-1)` in time interval 't' on linear path. Then it covers certain distance at constant speed of `30 km h^(-1)` in the same time interval. What is the average speed of the vehicle ?

Options

A. `25 km h ^(-1)`
B. `24 km h ^(-1)`
C. `50 km h ^(-1)`
D. `12 km h ^(-1)`

Answer

A

Explanation

The vechicle covers both the distances in equal time intervals,
`therefore` Average speed `= ( 20 km h ^(-1) + 30 km h ^(-1))/( 2) = 25 km h ^(-1)`