A set of trading cards sells for 10 dollars before tax . After sales tax, its costs 12 dollars. What is the sales tax rates ?

Tax amount = 12 - 10

Tax amount = 2 dollars

2 dollars is what percent of 10 dollars?

2 = 10x

2/10 = x

1/5 = x

0.20 = x

20 percent = x

Correct?