What is the distance between the islands?

Question

A boat travels x miles per hour from one island to another in 2.5 hours. The boat travels 5 miles per hour faster on the return trip of 2 hours. What is the distance between the islands?

Answer 1

Speed to the island is x

 

Speed on the return is x+5

 

the distance is the same so

 

2.5*x = 2*(x+5). It took 2.5 hrs to get there and 2 hrs to return

 

now solve. 

 

2.5*x = 2x + 10

 

.5x = 10

 

x=20

 

So the distance between islands is 2.5 * 20 = 50 miles

 

hope this helps