Question

Eighteen marbles are dropped into a jar. There are 8 black marbles, 7 red ones, and 3 silver ones. Marbles are taken from the jar without looking. Use this information to answer these two questions.

1. If one marble is taken, what is the probability of taking a marble that is NOT black?

2. If two marbles are taken WITHOUT replacement, what is the probability of choosing a black marble first and a silver marble second?

Answer 1

1. 10/18

2. Black first = 8/18, without replacement, silver is 3/17. To find probability of all events occurring, multiply probability of individual events.

Answer 2

8/18