Probability - General Questions

One card is drawn at random from a well-shuffled pack of 52 cards. What is the probability that it is a face card?

A bag contains 5 red, 4 blue and 5 green balls. Two balls are drawn at random. What is the probability that both are red?

4 unbiased coins are tossed together. What is the probability of getting at least one head?

One card is drawn at random from a well-shuffled pack of 52 cards. What is the probability that it is a spade or an ace?

A letter is chosen at random from the word 'LOGIC'. What is the probability that it is a vowel?