Adrian recorded the grade-level and instrument of everyone in the middle school School of Rock below.
Seventh Grade Students
Eighth Grade Students
Instrument # of Students
Instrument # of Students
15
11
13
Guitar
Bass
Drums
Keyboard
Guitar
Bass
Drums
Keyboard
15 6 1
8
10
2
Based on these results, express the probability that a seventh grader chosen at
random will play an instrument other than keyboard as a percent to the nearest
whole number.