In a recent survey of 100 women, the following information was gathered.
36 use shampoo A.
46 use shampoo B.
37 use shampoo C.
19 use shampoos A and B.
11 use shampoos A and C.
10 use shampoos B and C.
9 use all three.
How many are using shampoos A and C, but not B (Region IV)?
A & B but not C
= A&B - all three
= 19-9
=10