there is a bag filled with 3 blue and 4 red marbles. A marble is taken at random from the bag, the colour is noted and then it is not replaced. another marble is taken at random. what is the probability of getting 2 reds ?
You can just use some sort of counting principle The first time you draw a read marble, your odds of getting 1 were 4/7 You are not replacing the marble. Your choice now is 3/6
