80% of what number equals 32?

• A. 40
• B. 60
• C. 80
• D. 32

Answer: (A)

Percent tells you a part of a whole, so you treat it as a multiplier. Eighty percent is eight-tenths. If eight-tenths of a number equals thirty-two, undo the multiplication by dividing by eight-tenths. Dividing by eight-tenths is the same as multiplying by five-fourths, so the number is thirty-two times five-fourths. Compute that as thirty-two times five divided by four. Thirty-two divided by four is eight, and eight times five is forty. So the number is forty.

Quick check: eight-tenths of forty is thirty-two, which matches.