Question

There are 5 blue marbles, 2 red marbles, and 3 green marbles in a bag. What is theprobability of selecting NOT a green marble? Your answer can be a fraction, decimalor percent.

Answer 1

Given

Total marbles 5+2+3 =10

`\begin{gathered} \text{probability of selecting blue=}(5)/(10)=(1)/(2) \\ \\ \text{porbability of selceting red =}(2)/(10)=(1)/(5) \\ \text{Probalility of selecting gr}een\text{=}(3)/(10) \\ \end{gathered}`

Now probability of NOT selecting green Marble

`\begin{gathered} \text{Probability of selecting NOT gr}een\text{ marbles=1-}(3)/(10) \\ \\ \text{Probability of selecting NOT gr}een\text{ marbles=}(1)/(1)\text{-}(3)/(10) \\ \text{Probability of selecting NOT gr}een\text{ marbles=}(10-3)/(10)=(7)/(10) \end{gathered}`

Alternatively (second method )

Probability of selecting NOT a green marble means you will be selecting either blue marbles or red marbles

`\text{Probability of selecting NOT a green =}(5)/(10)+(2)/(10)=(7)/(10)`

The final answer

`\begin{gathered} \text{Fraction }(7)/(10) \\ \text{Decimal 0.7} \\ \text{Percetages 70\%} \end{gathered}`