A jar contains 10 red marbles numbered 1-10, 8 blue marbles numbered 1-8, and 12 white marbles numbered 1-12. A marble is drawn at random from the jar. Find the probability of the given event.

Question

(a)The marble is red.

(b) The marble is not red.

(c) The marble has the number 3 written on it.

(d) The marble is blue with the number 1 written on it.

(d) The marble has the number 19 written on it.

Answer 1

Probability = # of successes/total # of possible outcomes

For this problem, there are 30 marbles, the denominator for all of them will be 30.

(a) There are 10 red marbles

10/30 = 1/3

(b) There are 20 that are not red

20/30 = 2/3

(c) There are 3 marbles with a 3 on them

3/30 = 1/20

(d) There is 1 marble that is blue with a 1 on it.

1/30

(e) There are none of these

0/30 = 0