A bag contains 10 red, 5 blue and 7 green balls. A ball is drawn at random. Find the probability of this ball being a
(i) red ball
(ii) green ball
(iii) not a blue ball
No. of red ball = 10
No. of blue ball = 5
No. of green balls = 7
If a ball is drawn out of 22 balls (5 blue
+ 7 green + 10 red), then the total number of outcomes are
n(S) = 22
(i) Let E1 = Event of getting a red ball
∴ n(E1) = 10
(ii) Let E2 = Event of getting a green ball
n(E2) = 7
(iii) Let E3 = Event getting a red ball or a green ball i.e., not a blue ball.
n(E3) = (10 + 7) = 17
28