math
posted by Daniel .
In a recent survey of 100 women, the following information was gathered.
33 use shampoo A.
37 use shampoo B.
49 use shampoo C.
12 use shampoos A and B.
5 use shampoos A and C.
9 use shampoos B and C.
2 use all three.
Use the figure to answer the question in the problem.

Calculate the monthly finance charge for the following credit card transaction. Assume that it takes 10 days for a payment to be received and recorded and that the month is 30 days long. (Round your answer to the nearest cent.)
$500 balance, 20% rate, $400 payment, adjusted balance method 
In a recent survey of 100 women, the following information was gathered.
46 use shampoo A, 44 used shampoo B, and 43 used shampoo C, 13 used a and b and 17 used a and c and 12 used b and c, and 7 used all 3