Chapter 9.3, Problem 76PE

The number of calories burned per hour for three activities is given in matrix $N$ for a $140\text{-lb}$ woman training for a triathlon. The time spent on each activity for two different training days is given in matrix $T$ .

$\begin{array}{l}\text{ Calories/hr}\\ N=\left[\begin{array}{c}540\\ 400\\ 360\end{array}\right]\begin{array}{l}\text{Running}\hfill \\ \text{Bicycling}\hfill \\ \text{Swimming}\hfill \end{array}\end{array}$

$\begin{array}{l}\text{ Time}\\ \text{ Running Bicycling Swimming}\\ T=\left[\begin{array}{ccc}45\min & 1\text{ hr}& 30\min \\ 1\text{ hr}& 1\text{ hr }30\min & 45\min \end{array}\right]\begin{array}{c}\text{Day 1}\\ \text{Day 2}\end{array}\end{array}$

a. Which product $NT$ or $TN$ gives the total number of calories burned from these activities for each day?

b. Find a matrix that gives the total number of calories burned from these activities for each day.