Question

A bag has 4 green marbles, 3 red marbles, and 3 yellow marbles. What is the probability that you pick

Answer 1

Answer: 1/10

Explanation: 3/9 times 3/10 equals 9/90, simplify and you'll get 1/10

There are 3 red, that is where the first numerator comes from and there are 10 marbles so that is where the denominator comes from. There are 3 yellows, hence the second numerator but as we have taken a marble out there are now only 9 marbles in total.

Answer 2

$|\Omega|=10\cdot9=90\\ |A|=3\cdot3=9\\\\ P(A)=\dfrac{9}{90}=\dfrac{1}{10}=10\%$