Question

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 blues?

Answer 1

8/18

Explanation:

the probability of the marble being red is 5/9 and it being blue is 4/9

so the probability of it being a blue marble two times is

4/9 + 4/9

=

8/18

Answer 2

7 out of 9 , 7:9, 7/9

because 4+5=9
9-2= 7