A problem in mathematics is given to three students $A, B$, and $C$, whose chances of solving it independently are $\frac{1}{2}, \frac{1}{3}$, and $\frac{1}{4}$ respectively. Find the probability that the problem is solved.

A card is drawn from a well-shuffled standard pack of 52 cards. What is the probability that the card drawn is: (a) A King or a Spade? (b) Neither a King nor a Queen? (c) A face card or an Ace?