Last month Bill's electric bill was $80.77. This month it is $69.06. what is the percent decrease?

$80.77 - $69.06 = $11.71 , I don't understand multiply decimal by 100 to get the decrease

2 answers

You only did the first part.

You forgot to divide 11.71 by 80.77

100 (11.71 / 80.77) = ?
Whats the answer