You would make them all over 10, then subtract them from [tex]\frac{10}{10}[/tex]
The probabilities are [tex]\frac{1}{10}, \frac{2}{10}, \frac{5}{10}[/tex]
Add them together, you get, [tex]\frac{8}{10}[/tex]
[tex]10-8=2[/tex] so [tex]x=\frac{2}{10} or \frac{1}{5}[/tex]
