Question

There is a bag filled with 6 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

What you need to remember for answering this question is that the probability of any event is the number of sample points in the event divided by the number of sample points in the sample space.

If you have multiple trials and if the sampling is with replacement then, no matter how many samples are drawn, the probabilities remain the same for each trial.