Question

There is a bag filled with 3 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 at least 1 blue?

Answer 1

The probability of not getting any blue marbles on the first draw is 5/8. The probability of not getting any blue marbles on the second draw is also 5/8.

So the probability of not getting any blue marbles on either draw is (5/8) x (5/8) = 25/64.

Since we want to find the probability of getting at least 1 blue, we can subtract the probability of not getting any blue from 1:

1 - 25/64 = 39/64

So the probability of getting at least 1 blue is 39/64.