at 1 pm, you start out on your bike at 12 mph to meet a friend who lives 8 miles away. at the same time, the friend starts walking toward you at 4 mph. at what time will you meet your friend?

 1:30 PM

It takes 30 minutes

Explanation:

x = number of hours traveled

We'll use the equation

distance = rate*time

You bike at a rate of 12 mph and do so for x hours. That means you travel 12x miles based on the equation above. Your friend travels 4x miles for similar reasoning. Overall, the two of you travel a combined distance of 12x+4x = 16x miles. This combined distance is set equal to the 8 miles (distance between your houses) and you solve for x.

16x = 8

x = 8/16

x = 1/2

x = 0.5

Recall x is the number of hours, so that means it takes 1/2 an hour for the two of you to meet. This is equivalent to 30 minutes since 1/2*60 = 30.

If all of this starts at 1 PM, then you'll meet up at 1:30 PM since we add on 30 minutes to 1 PM to get to this moment in time.

Extra info:

You travel 12x = 12*0.5 = 6 miles

Your friend travels 4x = 4*0.5 = 2 miles

Total distance = you+friend = 6+2 = 8 miles

This helps confirm the answer.