At marble middle school, 35% of the students are 6th graders, 32% are 7th graders, and the rest are 8th graders. what percent are 8th graders?

All the students in that Middle School combined would equal 100%. So just add 35% and 32%, and subtract that answer from 100 to find out the percent of eighth graders.

35% + 32% = 67%

100% – 67% = 33%

The percent of 8th graders at Marble Middle School is 33%