Question

40% of the students at Rockledge Middle School are musicians. 75% of those musicians have to read sheet music when they play their instruments. If 38 of the students can play their instruments without reading sheet music, how many students are there at Rockledge Middle School?

Answer 1

A total of 380 students at Rockledge Middle School

Explanation:

For this problem since the only whole number they give you is 38, you work backwards, first finding the number of students who needs music sheets

If 75% need music sheets, it means 25% doesn't. The 38 is equal to 25% then 38*3 would give you the number of students who needs music sheets

38*3 = 114

114+38 = 152 is the number of students who are musicians

152 is 40% of the students

100-40-40-20=0 (if 100 is the total number of students and 40 is the musicians and 20 is half the musicians)

152/2 = 76

152+152+76 = 380

The total number of students is 380

Check:

380*40% is 152 (number of musicians)

152*75% = 114 (number of students that need music sheets)

152-114 = 38 (number of students that doesn't need music sheets)