Question

You have 40 minutes to exercise at the gym, and you want to burn 300 calories total using both

Answer 1

A and b are the minutes spent on machine A and machine B, respectively.

a+b = 40
b = 40-a

8a + 6b = 300
8a + 6(40-a) = 300
8a + 240 - 6a = 300
2a = 60
a = 30
b = 40-a = 10

30 minutes on machine A and 10 minutes on machine B