Question

Mrs. Anderson has a bag of marbles. The first bag

contains 6 red marbles, 5 blue marbles, and 4 green
marbles. Mrs. Anderson will select 1 marble at random.
What is the probability that Mrs. Anderson will NOT
select a blue marble?

A. 1/3 B. 1/2 C. 1/10 D. 2/3

Answer 1

`P(Not\ Blue) = (2)/(3)`

Explanation:

Given

`Red = 6`

`Blue =5`

`Green = 4`

Required

The probability of not selecting blue.

This means that any of the other colors is selected.

So, we have:

`P(Not\ Blue) = P(Red) + P(Green)`

`P(Not\ Blue) = (Red)/(Total) + (Green)/(Total)`

`P(Not\ Blue) = (6)/(15) + (4)/(15)`

Take LCM

`P(Not\ Blue) = (6+4)/(15)`

`P(Not\ Blue) = (10)/(15)`

Divide by 5/5

`P(Not\ Blue) = (2)/(3)`