A bag has 10 marbles in it: 2 red, 2 green, 2 blue, 2 yellow, and 2 black. You pick a marble out of the bag one at a time and then replace it. On average, how many marbles would you have to pick before you select at least one of each color? Use the data below as four trials. Should you use more trials? red green red red yellow green red red blue black
black green black red yellow blue
red blue red yellow yellow green black
green green red yellow red black red green black black red blue

Select one:
a. 6 marbles; no, the number of trials is sufficient.
b. 8.75 marbles; no, the number of trials is sufficient.
c. 8.75 marbles, yes, more trials are needed.
d. 10.5 marbles, yes, more trials are needed.