Probability - General Questions

Two dice are thrown together. What is the probability that the sum of the numbers is 12?

2 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 heart?

One card is drawn at random from a well-shuffled pack of 52 cards. What is the probability that it is a number card (2 to 10)?

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