Question

An urn contains 6 yellow, 5 blue and 2 white marbles. If three marbles are picked at random, what is the probability that at least one is blue?

Answer 1

Total Number of Marble in bag :- 6 + 5 + 2 = 13 marbles

No. of favourable outcome :- 5

P(E) = No. of favourable outcomes / Total No. of favourable outcomes

P(E) = 5/13

Answer 2

Answer:

115/143.

Step-by-step explanation:

Summation of the balls present in the urn = 6+5+2 = 13.

Summation of the non-blue balls present in the urn = 6+2=8.

Therefore, the total outcome will be = 13C3=286.

For finding out the probability of getting atleast one blue ball there are three the conditions:- 1 blue*2 non blue + 2 blue*1 non blue + 3 blue balls.

So, the probability will be 5C1x8C2 + 5C2x8C1 + 5C3 which on solving we will get as 230.

Hence, the probability of getting atleast one blue ball is 230/286=115/143.