Question

You are given a sheet of cardboard that is 8.0 in. x 11.0 in. how many full circles with a diameter of 3.0 inches can you cut from the cardboard? what is the percentage of waste if the excess cardboard (outside the circles) is thrown away?

Answer 1

The answer is there are eight circles that can be cut from an 8.0 x 11.0 in sheet but nine circles won’t fit.
Area of 8 circles is pir^2 = 8pi(1.5)^2 = 56.55 in^2

Total area of the cardboard = (8.0 in) (11.0 in) = 88.0 in^2
Area of waste = 88 in ^2 – 56.55 in^2 = 31.35 in^2
Percent of waste = 31.35 in^2 / 88.0 in^2 x 100% = 37.5% is the answer.