Answer 1

\[\text{ Number of red marbles }= 5\]
\[\text{ Number of white marbles } = 8\]
\[\text{ Number of green marbles } = 4\]
\[\text{ Total number of marbles in the bag } = 5 + 8 + 4 = 17\]
\[ \therefore \text{ Total number outcomes }= 17\]

\[\text{ Let A be the event of drawing a red ball }. \]
\[ \therefore P\left( A \right) = \frac{\text{ Number of favourable outcomes }}{\text{ Total number of outcomes }} = \frac{5}{17}\]