Answer in Statistics and Probability for IDK #251080

There is a bag filled with 4 blue and 5 red marbles.

A marble is taken at random from the bag, the colour is noted and then it is replaced.

Another marble is taken at random.

What is the probability of getting 2 of the same colour?

There are total 9 marbles, out of which there are 4 blue and 5 red marbles.

Probability of getting blue marbles in first turn will be “frac{4}{9}” .

Now, since the ball is replaced, the probability of again getting the blue ball will be same equal to “frac{4}{9}”

Now, from the multiplication theorem of probability, the probability of getting 2 blue balls will be:

“frac{4}{9}timesfrac{4}{9}=frac{16}{81}”