80% of the students in Lea’s class earned an A or a B on the weekly math test. If 20 students got an A or a B, how many students are in Lea’s class?

Will give Brainliest!!

P.S. This is 6th Grade math on Edge 2020
Here are the options:
0 20 is 80% of what number?
0 20 × 4 = 80, so 100 × 4 = 400 students
0 20 + 60 = 80, so 100 + 60 = 160 students
0 80 ÷ 4 = 20, so 100 ÷ 4 = 25 students
0 80 – 60 = 20, so 100 – 60 = 40 students