Question bellow

Question

Suppose you have entered aa 101-mile biathlon that consists of a run and a bicycle race. During your run, your average velocity is 7 miles per hour, and during your bicycle race, your average velocity is 20 miles per hour. You finish the race in 7 hours. What is the distance of the run? What is the distance of the bicycle race?

Answer 1

101 = 7R + 20B where R= time running B= time biking

7= R+ B, multiply by 7

49 =7R +7B subtract from the 1st equation to get

52 = 13B

B=52/13 = 4 hours biking

20B = 20(4) = 80 miles biking

21 miles running for 3 hours

101 = 3(7) + 4(20) = 21 + 80