Question

a teacher reported 1/5 made A's, 1/4 made B, 1/3 made C's, 1/6 made D's, and 12 made F's How many are in the class

Let X = the number of students

57/60
+
12
-------

Answer 1

The sum is this:
X = (1/5 + 1/4 + 1/3 + 1/6)*X + 12

X = (57/60)*X + 12

Simplify and solve for X

Answer 2

that's my problem i do not know how to simplify.