Question

A bag of marbles contains 2 blue marbles, 4 red marbles 6 green marbles

Answer 1

We start with 17 marbles, 4 of which are red. So P(first marble is red) = 4/17. Since the red marble is not replaced, there are now 16 marbles, 3 of which are red. So P(second marble is red) = 3/16.

The correct calculation is

P(red, then red) = 4/17 × 3/16