Grayson recorded the grade-level and instrument of everyone in the middle school School of Rock below. Seventh Grade Students Instrument # of Students Guitar 14 Bass 6 Drums 2 Keyboard 10 Eighth Grade Students Instrument # of Students Guitar 7 Bass 5 Drums 10 Keyboard 7 Based on these results, express the probability that a seventh grader chosen at random will play the bass as a percent to the nearest whole number.