If a cyclist is traveling at 25 miles per hour on a country highway, what is his speed in feet per second? (remember that a mile is 5280 feet.)

Here is the solution based on the given problem above.
Given: 25miles/hour = speed of the cyclist
           ? = speed in feet/second
           1 mile = 5280 feet
           1 hour = 3,600 seconds
In order to get the result, we need to get first how many feet is 25 miles.
so, 25 miles is equivalent to 132,000 feet.
and 1 hour = 3,600 seconds
So, it is 132,000 feet/3,600 seconds. Let us simplify this.
So the answer would be 36.67ft/second. 
I hope this is the answer that you are looking for.