Question

A bag has 2 yellow, 7 red, and 1 green marble. What is the probability of picking a yellow marble, replacing it, and then picking another yellow marble?

Answer 1

2 yellow marbles, 7 red marbles, 1 green marble.....total of 10 marbles

probability of first picking a yellow marble : 2/10 reduces to 1/5
replacing the marble
probability of picking another yellow marble : 2/10 reduces to 1/5

probability of both is : 1/5 * 1/5 = 1/25 <==