Question

A bag contains 5 black, 7 red and 3 white balls. A ball is drawn from the bag at random. Find the probability that the ball drawn is not black.

Answer 1

Total no. of possible outcomes = 15 {5 black, 7 red and 3 white balls}

E ⟶ event of drawing black ball

No. of favourable outcomes = 5 {5 black balls}

P (E) = `5/15`

= `1/3`

`barE` ⟶ event of not drawing black ball

`P (barE)= 1 - P(E)`

= `1 - (1/3)` 

= `2/3`