Total number of marbles:
[tex]6 + 5 + 3 + 1 = 15 \: marbles[/tex]
Total number of possibilities excluding white marbles:
[tex]6 + 5 + 1 = 12 \: marbles[/tex]
The probability of an event occuring is given by:
[tex]p(a) = \frac{number \: of \: possibilities}{total \: number \: of \: possibilities} [/tex]
[tex]p(a) = \frac{12}{15} = \frac{4}{5} [/tex]
Letter C
