25 points! a) my friend sets out walking at a speed of 3 miles per hour. i set out behind her 5 minutes later at 4 miles per hour. when i start walking, how many miles has my friend traveled? b) my friend sets out walking at a speed of 3 miles per hour. i set out behind her 5 minutes later at 4 miles per hour. for how many minutes will my friend have been walking when i catch up to her?

A) So if your friend started walking 3 miles per hour for 5 minutes the first step to take is to divide 5 by 60 because she walked 5 out of 60 minutes for 3 mph. You then get the fraction 1/12. Next you want to multiply 3 mph by 1/12 to get the answer 1/4 miles. So the answer for A is the girl walked a quarter (0.25 miles) in the 5 minute headstart. 

B) Based off the previous answer she should be 0.25 miles ahead of you by the time you start walking. For this problem you would need a graph, the equations for the graph I got were y=3x+0.25 and y=4x+0. Simply graph after this and find the intercept, to determine the amount of time it took you need to view where the two lines intercept, and the x value is the amount of time it took. The x value I got was 0.25. So 60*0.25 is 15, it took you 15 minutes to catch up with her at 1 miles from the start point.