There are 15 lottery tickets available. Roy know that 6 of them are winning. If Roy picks one ticket at random what is the probability that it will be a winning ticket
[tex]the \ probability= \frac{the \ number \ of \ favorable \ cases}{the \ number \ of \ posible \ cases} \\ \\\boxed{p= \frac{6}{15}=\frac{2}{5}}[/tex]