Question

Jim is choosing between two exercise routines.In Routine #1, he does only running, burning 15.5 calories per minute.In Routine #2, he burns 26 calories walking. He then runs at a rate that burns 10.3 calories per minute.For what amounts of time spent running will Routine #1 burn more calories than Routine #2?Use t for the number of minutes spent running, and solve your Inequality for t.

Answer 1

Suppose Jim runs in routine 1 and 2 for t minutes.

In routine (1), he burns 15.5 calories per minute by running only.

Therefore, in routine (1), Jim burns 15.5t calories.

In routine 2, Jim burns 26 calories by walking and 10.3 calories per minute by running.

Therefore, in riutine (2), total amount of calories that Jim burns is

`26+10.3t`

Accordingly,

`\begin{gathered} 15.5t>26+10.3t \\ 15.5t-10.3t>26 \\ t>5 \end{gathered}`

So, Jim should run more than 5 minutes