Question

a person prepared a meal of the following items each having the given number of grams of proteins, carbohydrates and fats respectively
Beef stew:25,21,22
coleslaw:3,10,10 
icecream:7,25,6
if the calorie count of each gram of protein, carbohydrate and fat is 4.1 cal/g,3.9 cal/g and 8.9 cal/g respectively
find the calorie count of each item by matrix multiplication

Answer 1

[tex]Meal = \left[\begin{array}{ccc}Beef\ Stew\\Coleslaw\\Ice\ Cream\end{array}\right] = [/tex]
$\left[\begin{array}{ccc}Proteins&Carbohydrates&Fats\end{array}\right] = \left[\begin{array}{ccc}25&21&22\\3&10&10\\7&25&6\end{array}\right]$

$Calories = \left[\begin{array}{ccc}protein\\Carbohydrate\\Fat\end{array}\right] = \left[\begin{array}{ccc}4.1\\3.9\\8.9\end{array}\right] cal/g$

[tex]Calorie\ Counts = [ Meal ] [ Calories ] = \left[\begin{array}{ccc}25*4.1+21*3.9+22*8.9\\3*4.1+10*3.9+10*8.9\\7*4.1+25*3.9+6*8.9\end{array}\right] \\ [/tex] Calories