There are A, B, and C types of problem set, and each type of
problem set contains 3000, 2000, 5000 problems, respectively.
Suppose you can solve A-type problem with 90% probability, B-type
problem with 20% probability, and C-type problem with 60%
probability. To pass graduation exam, you must solve both of two
questions randomly chosen from the total problem set (out of 10,000
problems). Answer the following questions:
1) What is the probability that you pass the graduation exam?
2)...