geometry 2
posted by me .
Xenia is ordering a cake for her friend’s wedding. She knows that there will be 110 guests at the wedding, and she is trying to decide how large a cake to order. She has been told that each guest should get a piece of cake that is 4 inches by 4 inches. She would like to buy a tiered, square threelayer cake and is trying to decide which sizes of cakes to order. Which combination of cakes should she get? The available sizes, in inches, are:

32 × 32
28 × 28
24 × 24
20 × 20
16 × 16
12 × 12
8 × 8 
A = 4 * 4 = 16in^2 / slice,
At=16in^2/slice * 110slices = 1760in^2
needed.
Choose Sizes:
32 x 32 = 1024 in^2.
28 x 28 = 784 in^2.
Total = 1024 + 784 = 1808 in^2.
Surplus = 1808  1760 = 48 in^2 = 3
slices. 
8x8, 12x12, 16x16