Question

1. A motorboat leaves a harbor and travels at an average speed of 15 mph toward an island. The average speed on the return trip was 10 mph. How far was the island from the harbor if the total trip took 5 hours

Answer 1

Answer:

  30 miles

Step-by-step explanation:

Let d represent the distance to the island. The relation between time, speed, and distance is ...

  time = distance/speed

so the total time for the round trip is ...

  d/15 +d/10 = 5

Multiplying by 30, we get

  2d +3d = 150

  d = 150/5 = 30

The island was 30 miles from the harbor.