Nasim recorded the grade-level and instrument of everyone in the middle school School of Rock below.
Seventh Grade Students
Instrument # of Students
Guitar 2
Bass 10
Drums 15
Keyboard 2
Eighth Grade Students
Instrument # of Students
Guitar 3
Bass 2
Drums 2
Keyboard 5
Based on these results, express the probability that an eighth grader chosen at random will play the drums as a fraction in simplest form.
