Question

A bag contains 4 red, 5 black and 6 white balls. A ball is drawn from the bag at random. Find the probability that the ball drawn is: 

red 

Answer 1

\[\text{ Number of red balls }= 4\]
\[\text{ Number of black balls } = 5\]
\[\text{ Number of white balls }= 6\]
\[\text{ Total number of balls in the bag }= 4 + 5 + 6 = 15\]
\[\text{ Therefore, the total number of cases is 15 }. \]

\[\text{ Let B denote the event of getting a red ball }. \]
\[\text{ Number of favourable out comes,i.e. number of red balls 4 }\]
\[P\left( B \right) = \frac{\text{ Number of favourable outcomes }}{\text{ Total number of outcomes }} = \frac{4}{15}\]