Answer:
Here's how to solve the problem
Explanation:
50% of participants are in 6th grade.
100% - 50% = 50
0.3, when converted to percentage form is 30%
50% - 30% = 20%
This remaining 20% is how many participants, out of the whole, are in the 7th grade
20% = 0.2 = 2/10 = 20/100