probablility question?

Question

a bag contains 6 red discs, 4 blue discs and 5 green discs.
A fair dice has 4 faces painted red and the other 2 faces painted blue.

Lisa takes a disc at random from the bag and records its colour.
Lisa then throws the dice twice and each time records the colour of the face it lands on.

Work out the probability that, of the three colours lisa records, exactly two are the same.

Answer 1

There are 15*6*6 different ways to pull items = 540

First, for the die, there are three different ways to roll: RR, RB, BB. There are a total of 36 possibilities, with 16 of them being RR, 16 being RB, and 4 being BB.

There are 6 ways to pull a R disc. There are two different situations to get a double color now - either rolling RB or BB. There are 16 ways to get the two die to come up RB and 4 ways to have them both come up B: 6(16+4) = 120 ways

There are 4 ways to pull a B disc. There are two different situations to get a double color now - either rolling RR or RB. There are 16 different ways to get RR, and 16 ways to get RB: 4(16+16) = 128 ways

There are 5 ways to pull a G disc. There are two different situations to get a double color now - either rolling RR or BB. There are 16 different ways to get RR, and 4 ways to get BB: 5(16+4) = 100 ways

-> (120+128+100)/540 = 348/540 = 0.64 probability

Answer 2

It seems to me that these referring conditional probability to you. If you prune encontra the theorem of Bayes it goes to you to help to solve the problem. Luck!

Answer 3

I think you need a night out sunshine