Chapter 6.3, Problem 55SPR

To determine

To prove:

The person has done one of these activities for more than an hour

Explanation of Solution

Given information:

Time spent in the pool: $\mathrm{P}$

Time spent lifting weights: $\mathrm{W}$

Proof:

Step 1:

Consider, $\mathrm{P}\le 1$ and $\mathrm{W}\le 1$

Step 2:

  $\mathrm{P}+\mathrm{W}\le 2$

Step 3:

It contradicts the given problem statement. Therefore, it clearly shows that that person has spent more than an hour for one of these activities.

Hence proved