A box contains 5 red marbles, 8 white marbles and 4 green marbles.
∴ Total number of marbles, n(S)
= 5 + 8 + 4 = 17
(i) Probability that the 1 red marble drawn is n(A) = 5
∴ Probability, P(A) =
n(A)
n(S)
=
5
17
(ii) Possibility that 1 white marble drawn, n(B) = 8
∴ Probability, P(B) =
n(B)
n(S)
=
8
17
(iii) Possibility that 1 not green marble ?
P(C) = 17 – 4 = 13 (∵ Except 4 green marbles)
∴ Probability, P(C) =
n(c)
n(S)
=
13
17