Question

A bag contains 5 red balls, 6 white balls, 7 green balls, 8 black balls. One ball is drawn at random from the bag. Find the probability that the ball drawn is neither white or black.

Answer 1

Sample space (S) = 5 + 6 + 7 + 8

n(S) = 26

Let A be the event of getting a white ball

n(A) = 6

P(A) = `(n(A))/(n(S))`

= `6/26`

= `3/13`

Let B be the event of getting a black ball

n(B) = 8

P(B) = `(n(B))/(n(S))`

= `8/26`

= `4/13`

P(A ∪ B) = P(A) + P(B) 

= `6/26 + 8/26`

= `14/26`

= `7/13`

Probability of neither white or black P(A ∪ B)’ = 1 – P(A ∪ B)

= `1 - 14/26`

= `(26 - 14)/26`

= `12/26`

= `6/13`