10. I love Chex Mix. My favorite things in the mix are those little pumpernickel chips. But they're relatively rare compared to the other ingredients. That's OK, though, since my second-favorite are the Chex pieces themselves, and they're pretty abundant. I don't know what the exact ratios are, but let's suppose that it's 50% Chex cereal, 30% pretzels, 10% crunchy bread sticks, and 10% my beloved pumpernickel chips. Suppose I've got a big bowl of Chex Mix: 1,000 total pieces of food. If I eat three pieces from the bowl, (a) what's the probability that at least one of them will be a pumpernickel chip? And (b) what's the probability that either all three will be pumpernickel chips or all three will be my second-favoriteChex pieces?