Question

A bag contains 6 black ,5 blue and 4 pink balls.if 3 balls are drawn one by one with replacement ,then what is the probability that all the ball are blues

Answer 1

No. of Blue Balls=5

No. of Black Balls=6

No. of Balls drawn=3

P(2 balls are blue & 1 ball is black)

=no. of possible ways of getting [2 balls are blue & 1 ball is black]/no. of possible ways of getting[3 Balls]

Now,

no. of possible ways of getting [2 balls are blue & 1 ball is black]

=(no. of possible ways of getting [2 balls are blue]) *( no. of possible ways of getting[1 ball is black])

=5C2 * 4C1

=10*4

=40

no. of possible ways of getting[3 Balls]

=9C3

=84

So,

P(2 balls are blue & 1 ball is black)

=40/84

=.47619

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hope it helps !!☺☺