After 18 months, how much more will a $2,500 investment make at a 5.5% simple
interest rate than a 4% simple interest rate?
A. $48.95
B. $56.25
C. $64.50
D. $72.10

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?