Question

A bag contains 5 red, 8 white and 7 black balls. A ball is drawn at random from the bag. Find the probability that the drawn ball is not black

Answer 1

Total no. of possible outcomes = 20 {5 red, 8 white & 7 black}

Let E ⟶ be event of getting black ball

No. of favourable outcomes = 7 {7 blackl}

Probability, P(E) =`"No.of favorable outcomes"/"Total no.of possible outcomes"`

P(E) = 7/20

(`barE` )⟶ event of not getting black ball

𝑃(`barE` ) = 1 – P(E) 

= 1 − 7/20 =13/20