Statistics/Probability Assignment

5. Find the probability of getting a sum=7 when two fair dice are rolled.

For questions 18-20, consider a box with 3 red and 5 blue balls.

18. If two balls are drawn at random, what is the probability that they have the same color?

19. If two balls are drawn at random, what is the probability that they have different colors?

20. If three balls are drawn at random, what is the probability that at least one of them is blue?