In a recent survey of 100 women, the following information was gathered.

39 use shampoo A.
42 use shampoo B.
48 use shampoo C.
14 use shampoos A and B.
15 use shampoos A and C.
12 use shampoos B and C.
8 use all three.
Use the figure to answer the question in the problem.

How many are using shampoos A and C, but not B (Region IV)?

This has been answered several times. See Related Questions below.