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 cup on top of the stack is not green

Answer 1

the probability is calculated by dividing the non-green cups by the total of them:
total = 12
non-green = 4 + 5 = 9
probability of non-green = 9/12 = 0.75 = 75%