80% is the change from 20 to 36
Calculation steps:
[( 36 - 20 ) ÷ 20] x 100 = 80%
Formula
Percentage change = [(36 - 20) / 20] x 100
Subtract the new number by the original number
36 - 20 = 16
16 ÷ 20 = 0.8
0.8 x 100 = 80%
Example