Question

Two balls are drawn at random, with replacement from a box containing 9 black and 7 white balls. Calculate the probability of both balls are black.

Answer 1

Answer:

Probability of both ball are black is 81/256 = 0.32

Step-by-step explanation:

There are 9 black and 7 white balls. Thus, total number of balls is 16

Probability of an event E is given by

$P(E)=\frac{n(E)}{n(S)}$

Here, n(s) = 16

In the first drawn, the probability of getting a black ball is given by

$P(E_1)=\frac{9}{16}$

Now, replacement is allowed, hence the total number of balls in second drawn is also 16

The probability of getting a black ball in second drawn is given by

$P(E_2)=\frac{9}{16}$

Therefore, probability for both black balls is

$P(E)=P(E_1)\times P(E_2)\\\\P(E)=\frac{9}{16}\times \frac{9}{16}\\\\P(E)=\frac{81}{256}\approx 0.32$

Answer 2

Answer:

I hope answer is correct