Suppose a bag of marbles has 4 green, 2 red, 5 yellow, 1 brown, and 7 blue marbles. What is the probability of picking a green marble, replacing it, and then picking a brown marble? The probability of a student having a skateboard is 0.49 and the probability of having rollerblades is .57. What is the probability that a student has both a skateboard and roller blades? If 50% of your friends like coffee and 70% like hot cocoa, what is the probability that one of your friends likes both coffee and hot cocoa?