Can someone please help me with this Pre-Algebra problem? I’m trying to help my younger brother with his homework.

Question

At the picnic, twenty of the 80 students participated in the scavenger hunt. What percent of the students did

not participate in the scavenger hunt?

[A] 60%

[B] 75%

[C] 25%

[D] 100%

My brother got [C], is he correct?

Answer 1

20 participated

80 - 20 did not participate

80 - 20 = 60

60 / 80 = x / 100

3 / 4 = x / 100

3 / 4 = 75 / 100

75% dod not participate

Or

20 / 80 participated

1 / 4 participated

3 / 4 did not participate

75% did not participate

Answer 2