Question

You are biking at a speed of 18 miles per hour. You are 3 miles behind your friend, who is biking at a speed of 12 miles per hour. Write and solve an equation to find the amount of time it takes for you to catch up to your friend.

Answer 1

A. solve by logic:

You bike 18 miles per hour, and your friend, 12 miles per hour.

In one hour, you'd catch up 6 miles, so in half-an-hour you'd catch up 3 miles.

B. Solve by equations:

Let x=time needed in hours

18x-12x=3

6x=3

x=3/6=0.5 hours