Question

Charlene has 12 plastic cups.Of the 12 plastic cups,3 were green,4 are red,and 5 are blue.She stacks the cups into a single stack in random order. What is the probability that the cups on top of the stack is not green

Answer 1

So we have:
12 plastic cups total
3 green
4 red, 5 blue
the probability to have a non-green cup at the top of the stack is 9 out of 12, those are the non-green cups, so:
probability = 9/12 = 0.57 = 75%