The first thing we must do for this case is to define variables.
We have then:
x: vanilla wafers
y: chocolate wafers
We now write the system of equations:
4x + y = 45
x + y = 27
We solve the system of equations.
Using the graphical method, we observe that the lines intersect is:
(x, y) = (6, 21)
Thus,
x = 6
y = 21
Answer:
6 vanilla wafers
21 chocolate wafers