Question

There are three red marbles, four white marbles, five yellow marbles, and six black marbles in a bag.What is the probability of drawing two red marbles, if you don't replace the marble after you draw the first one?

Answer 1

There are total 18 marbles in a bag.
P(red marble) first drawn:
3/18=1/6
P(red marble) second drawn:
2/17
2/17×1/6=1/51. As a result, the probability of drawing two red marbles is 1/51. Hope it help!