a jar contains 4 blue marbles and 1 yellow marble. If Carol picks one marble without looking, what is the probability that she will pick a blue marble?

a 1 out 5
b 1 out of 4
c 3 out of 4
d not here

4 out of 5 because there are 5 total marbles, and 4 are blue. Thus the probability is 4/5. Your answer should be d. not here.