Math, asked by shivramnahak3669, 10 months ago

A box contains 5 white , 8 red ,9 black ball . two balls picked randomly what is pro they are not black

Answers

Answered by suraj809078
0

Answer:

p(not black) = 13/22

Step-by-step explanation:

I hope so this is ans

Answered by Anonymous
0

Given:

5 white, 8 red, 9 black balls

To find:

The probability of picking two balls that are not black

Solution:

The probability of picking two balls that are not black is 26/77.

We can find the probability by following the given steps-

We know that there are 5 white balls, 8 red balls, and 9 black balls.

So, the total number of balls=number of white balls+number of red balls+number of black balls

=5+8+9

=22

The number of balls that are not black=red balls+white balls=5+8=13 balls

Out of these, we have to pick out 2 balls randomly.

We will use the concept of combinations where nCr=n!/r!(n-r)!

The number of ways of choosing 2 balls that are not black=13C2

=13!/2!×11!

=13×12×11!/2!×11!

=13×12/2

=13×6

=78

Similarly, the total number of ways of choosing two balls=22C2

=22!/2!×20!

=22×21×20!/2!×20!

=22×21/2

=11×21

=231

The probability of picking two balls that are not black=13C2/22C2

=78/231

=26/77

Therefore, the probability of picking two balls that are not black is 26/77.

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