66 is what percent of 120?

You would create a proportion ... so since percent is out of 100, you would do 66/120 = x/100. Then you would cross multiply, solving 66x100 (which equals 6000). The final step is to divide that product by the leftover number, which is 120. So you basically would do 6600/120 to get the answer.

120 = 100%

66 = x %

120x = 6600

x = 6600

120

x = 55

S = 55%