Question

A box is filled with 12 red cards 2 blue cards and 4 green cards a card is chosen at random from the box what is the probability that the card is not blue write your answer as a fraction in simplest form

Answer 1

There are 12+2+4=18 cards in total. The probability to get a not-blue card is

$\begin{gathered} P(\text{not blue) = 1 - P(blue)} \\ P(\text{not blue) =}1-\frac{2}{18} \end{gathered}$

which gives

$\begin{gathered} P(\text{not blue})=1-\frac{1}{9} \\ P(\text{not blue})=\frac{9}{9}-\frac{1}{9} \\ P(\text{not blue})=\frac{9-1}{9} \\ P(\text{not blue})=\frac{8}{9} \end{gathered}$

then, the probability that the card is not blue is 8/9.