Question

Bob took 20 math test last year if he failed 6 of them what percent of the math test did he pass

Answer 1

6 out of 20=what percent?
6/20=x%

percent means parts out of 100
x%=x/100

6/20=x/100
time both sides by 100
30=x
answer is 30% passed

100-30=70
70% is answer

Answer 2

70 %

6 is the 30% percent of 20, so 70% refers to the percent of the math test he passed