Mr. green music class, 3/12 of the students play guitar, 4/12 play violin. what fraction plays piano?

To find out how many students play piano, you need to add 3/12 + 4/12 and then find out the remainder.

3/12 + 4/12 = 7/12

Now we subtract that from 12/12 so you can find out what's left of the class.

12/12 - 7/12 = 5/12

Therefore, 5/12 of the class plays piano.