Question

Suzette ran and biked for a total of 34 mi in 3.5 h. Her average running speed was 6 mph and her average biking speed was 12.5 mph. Let x = total hours Suzette ran. Let y = total hours Suzette biked. Use substitution to solve for x and y. Show your work. Check your solution. (a) How many hours did Suzette run? (b) How many hours did she bike?

Answer 1

Answer:

From the information given

x is time for which she ran at speed of 6mi/h and

y is time for which she biked at speed of 12.5 mi/h

total time = 3.5 h

total distance = 34 mi

so

6x + 12.5y = 34 and

x + y = 3.5

x = 3.5 - y

6 ( 3.5 - y) + y = 34

6.5y = 13 which gives

y = 2 and this

x = 1.5

so suze ran for 1.5 h and biked for 2 h

CHECK

speed of run X time of run + speed of biking x time of biking must be = total distance covered

6 × 1.5 + 12.5 × 2 = 9 + 25= 34 mi

which is true