Probability with lollipops

Question

A bag has 3 RED lollipops, 7 BLUE lollipops, and 7 BLACK lollipops. You randomly pull a lollipop from the bag, put it back, and then pull out another one.

What is the probability of not getting a BLUE and then not getting a BLUE? write your answer as a fraction.

Answer 1

Hello Viviana,

The first time: you could pick any of the 10 lollipops that are NOT blue (you could pick one of the 3 reds or one of the 7 black) out of a bag containing 17 total lollipops. So the probability here is 10/17

The second time: since you put the first lollipop back, it'll be the same answer: you will stick pick any of the 10 NON-blue lollipops, and you will be choosing from a bag of 17 lollipops. So again, probability is 10/17

Probability of the first non-blue AND second NON-blue: you multiply the probabilities so (10/17)*(10/17) so your answer will be 100/289

Answer: the probability of not getting a BLUE and then not getting a BLUE is 100/289