Question

A pizza parlor offers pizzas with diameters of 8 in, 10 in, and 12 in. find the area of each size pizza. round to the nearest tenth. if the pizzas cost $9, $12, and $18 respectively, which is the better buy

Answer 1

Area of Pizza 1 = 50.24 sq. inch, Area of Pizza 2 = 78.5 sq. inch, Area of Pizza 3 = = 113.04 sq. inch

Thus, the pizza with diameter 8 inch is better to buy.

Explanation:

We are given three pizzas with three different diameters.

`diametre_1` = 8 inch ⇒
`radius_1` = 4 inch

`diametre_2` = 10 inch ⇒
`radius_1` = 5 inch

`diametre_3` = 12 inch ⇒
`radius_1` = 6 inch

Area of Circle = πr², where r is the radius of circle.

Area of Pizza 1 = 3.14 × 4 × 4 = 50.24 sq. inch

Area of Pizza 2 = 3.14 × 5 × 5 = 78.5 sq. inch

Area of Pizza 3 = 3.14 × 6 × 6 = 113.04 sq. inch

We are also given cost for each pizza.

`Cost_1` = $9

`Cost_2` = $12

`Cost_3` = $18

To choose which one is a better pizza to buy, we calculate cost per square inch.

Cost per sq. inch =
`\frac{\text{Cost of Pizza}}{\text{Area of Pizza}}`

Pizza 1 =
`(9)/(50.24)` = 0.18$ per sq. inch

Pizza 2 =
`(12)/(78.5)` = 0.15$ per sq. inch

Pizza 1 =
`(18)/(113.04)` = 0.16$ per sq. inch

Thus, the pizza with diameter 10 inch is better to buy.

Answer 2

Area od pizza, A = Pi*Diameter^2/4

A1 = Pi*8^2/4 = 50.27 in^2
A2 = Pi*10^2/4 = 78.54 in^2
A3 = Pi*12^2/4 = 113.10 in^2

Cost (C) per sq. in;
C1 = 50.27/9 = $5.59
C2 = 78.54/12 = $6.55
C3 = 113.10/18 = $6.28

The best buy is the first pizza with 8 in diameter as it costs the least per sq. inch.