Question

A cup contains 3 blue paper clips,2 red paper clips,and 5 silver paper clips.what is the probability of not drawing a red paper clip

Answer 1

Short Answer 0.8

Remark
The total number of possible draws is
3 Blue + 2 Red + 5 silver = 10
There are two ways of solving this, both of which will be used later on.

Method 1
If you don't draw a read paper clip, that means you will draw a silver or blue paper clip.
$\frac{Silver + blue}{10} = \frac{3 + 5}{10} = \frac{8}{10} = \text{0.8}$

Method Two
The other way is to draw a red one and take that probability away from 1. 
P(red) = $\frac{2}{10} = \text{0.2}$
1 - 0.2 = 0.8 Same answer.