A square-shaped cookie sheet has an area of 121 square inches each cookie needs 1 square inch of space. use every inch of the sheet as well as have the same number of cookies in each row and column.

Question

William is baking cookies for the bake sale. His square-shaped cookie sheet has an area of 121 square inches and each cookie needs 1 square inch of space. William needs to use every inch of the sheet as well as have the same number of cookies in each row and column. How many cookies should William have in each row and column?

Answer 1

Since William must have the same number of rows as columns, let the number of row be:

x = # of rows of cookies, then

x - # of columns of cookies, and each cookie occupies 1 sq. in. for each cookie

the total number of cookies is x*x or x², so:

x² = 121

x = 11 (this is the number of cookies in each row and column)