Finding the probability using combination.
Bob, Mary, and Jen go to dinner. Each orders a different meal. The waiter forgets who ordered which meal, so he randomly places the meals before the three diners. Let C be the event that a diner gets correct meal and let N be the event that a diner gets an incorrect meal. Find out the probability that:
a. No diner gets the correct meal.
b. Exactly one diner gets the correct meal.
c. Exactly two diners get the correct meal.
d. All three diners get the correct meal.