Question 153419
Music Class has 1 freshman, 6 sophmores and 11 juniors. 1/3rd of the class are seniors.
----------
Let "x" be the number in the class.
(2/3)rd of the class = 1 + 6 + 11
(2/3)x = 18
x = 27 ( # in the class )
# of seniors = (1/3)*27 = 9
==================================
You have it.
==================================
Cheers,
Stan H.