Question

The Smith family ordered 3 pizzas. Each pizza was cut into 12 equal slices. Each of the fivemembers of the Smith family ate the following amounts:Mr. Smith ate 1/2 of a whole pizzaMrs. Smith ate 1/4 of a whole pizzaLeon ate 2/3 of a whole pizzaJulie ate 1/3 of a whole pizzaAnna ate 7/12 of a whole pizza,How much pizza was left over?.

Answer 1

To find how much pizza was left we need to know how many slices of Pizza each member of the family ate, sum all the slices and subtract by the total amount of pizza they bought.

To find the total amount of pizza they bought, we need to multiply the number of pizzas by the number of slices they were cut. Therefore:

`\text{total slices = 12}\cdot3\text{ = 36}`

They bought a total of 36 slices of pizza. Now let's calculate the amount each member ate. To do that we need to multiply the fraction of the pizza they ate by the total number of slices in each pizza, in this case 12.

`\begin{gathered} Mr\text{. Smith = }(1)/(2)\cdot12\text{ = 6} \\ \text{Mrs. Smith = }(1)/(4)\cdot12\text{ = 3} \\ \text{Leon = }(2)/(3)\cdot12\text{ = 8} \\ \text{Julie = }(1)/(3)\cdot12\text{ = 4} \\ \text{Anna = }(7)/(12)\cdot12\text{ = 7} \end{gathered}`

Now that we know how many slices each person ate, we can sum all those slices to know how many the whole family ate.

`\text{whole family = 6+3+8+4+7 = }28`

We now subtract the total amount they bought by the amount they ate.

`\text{total left = 32 - 28 = 4}`

There were 4 slices left. If we want to calculate what fraction of a pizza that is we need to divide it by the number of slices the pizza was cut.

`(4)/(12)\text{ = }(1)/(3)`

So there were 4 slices left or 1/3 or a pizza.