Answer:
16 minutes on the elliptical trainer and 32 minutes on the treadmill.
Step-by-step explanation:
We have the following relation for the training in both machines:
[tex] 400 cal = 9 cal/min*t_{1} + 8 cal/min*t_{2} [/tex] (1)
Where:
t₁: is the time spent on the elliptical trainer
t₂: is the time spent on the treadmill
With:
[tex] t_{1} + t_{2} = 48 min [/tex] (2)
From equation (2) we have:
[tex] t_{1} = 48 min - t_{2} [/tex] (3)
By entering equation (3) into (1):
[tex] 400 cal = 9 cal/min*(48 min - t_{2}) + 8 cal/min*t_{2} [/tex]
[tex] 400 cal = 432 cal - 9 cal/min*t_{2} + 8 cal/min*t_{2} [/tex]
[tex] t_{2} = \frac{32 cal}{1 cal/min} = 32 min [/tex]
Now, we can find t₁:
[tex] t_{1} = 48 min - t_{2} = 48 min - 32 min = 16 min [/tex]
Therefore, you should spend 16 minutes on the elliptical trainer and 32 minutes on the treadmill.
I hope it helps you!