Probability - General Questions

A number is chosen at random from 1 to 40. What is the probability that it is a multiple of 4?

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

A number is chosen at random from 1 to 20. What is the probability that it is a multiple of 7?

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?

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