Question

Harry’s pizzeria is having a sale on medium and large pizzas. Medium pizzas are 10 inches in diameter and cost $7.99. Large pizzas are 14 inches in diameter and cost $14.99 Which size pizza is the better deal? Explain

Answer 1

Area = pi * r^2
.
A pizza with a 7-inch diameter has a radius of 3.5 inches.
Area = pi*3.5^2 = 38.48 sq. in.
.
A pizza with a 14-inch diameter has a radius of 7 inches.
Area = pi*7^2 = 153.93 sq. in.

.
The smaller pizza costs $5 = 500 cents, so it costs 500/38.48 = about 13 cents per sq. in.
.
It costs $12 = 1200 cents, so it costs 12/153.93 = about 8 cents per sq in.
.
The larger pizza is a better buy in terms of the cost per sq. in.
.
Done, hope that helped

Answer 2

The pizza that is the better deal is Large.

Medium Pizza : 
A^m = (3.14)*(5)^2
A^m= 78.5in^2
$7.99 / 78.5in^2 = $.10/1in^2

Large Pizza :
A^l = (3.14)*(7)^2
A^l = 153.86in^2
$14.99/153.86in^2 = $.09/1in^2