Question

You have 30 minutes to exercise at the gym. The Stairmaster burns 7 calories per minute, while the stationary bike burns 12 calories per minute. You want to burn 290 calories total using both machines. How much time should you spend on each machine?

Answer 1

14 min on Stairmaster

16 min on Bike

Explanation:

s = time on Stairmaster

b = time on bike

System of Equations:

s + b = 30

7s + 12b = 290

let 's' = 30-b

Substitution Method:

7(30-b) + 12b = 290

210 - 7b + 12b = 290

5b + 210 = 290

5b = 80

b = 16

s + 16 = 30

s = 14