Question

An urn contains 10 marbles: 4 red, 3 white, 2 blue, and 1 orange. (4 points) (a) What is the probability of drawing a marble that is red or white? (b) What is the probability of drawing a marble that is neither red nor white? (c) What is the probability of drawing a pair of marbles, one red and one white at the same time? (d) What is the probability of drawing a pair of marbles, one blue and one orange at the same time?

Answer 1

a) 0.70

b) 0.30

c) 12/45 =4/15

d) 2/45

Explanation:

a) Prob of drawing a marble red or white = No of red and white marbles/total marbles

= 7/10 = 0.70

b) Prob of drawing a marble neither red nor white = 1-7/10 = 0.30

c) Prob of drawing two marble one red and one white at the same time

=
`(4C1 (3C1)/(10C2 ) =(12)/(45)`

d) Prob of drawing two marble one blue and orange white at the same time

=
`(2C1 (1C1)/(10C2 ) =(2)/(45)`