A car traveled 75% of the way from town A to town B at an average speed of 90 miles per hour. The car travels at an average speed of S miles per hour for the remaining part of the trip. The average speed for the entire trip was 40 miles per hour. What is S ?	Choose the most appropriate option:
A) 15  B) 20  C) 25  D) 30  E) 37.5
Total distance = 100 miles (easier to work with %)   75% of the distance = 75 miles   25% of the distance = 25 miles   1st part of the trip → 75/90 = 0.833   2nd part of the trip → 25/S = t   Total trip → (75+25)/40 = 0.833+ t » 100/40 = 0.833 + t » 2.5 = 0.833+ t » t = 1.667   Back to 2nd part of the trip formula: 25/S = 1.667 » S = 15   15ns 15
<result>A</result>
A car traveled 75% of the way from town A to town B at an average speed of 90 miles per hour. The car travels at an average speed of S miles per hour for the remaining part of the trip. The average speed for the entire trip was 40 miles per hour. What is S ?