Note that 1 hour = 3600 seconds

The car is moving at the same speed, so it's speed is constant.

Now,

The distance the car travels in 3600 seconds is 65 miles, how many seconds does it take to travel 1 mile moving at the same speed. Since the speeds must be equal, we can equate the formulas:

Let the amount of seconds the car takes to travel 1 mile be .

.........Now we solve for

.................................I cross-multiplied (I left out the units).

Part (b) is similar