1. How many 5-card hands are possible from a standard deck of 52 playing cards if the cards are drawn without replacement?
2. How many ways can 3 pizza toppings be selected from a choice of 12 toppings if each topping can be chosen only once?
3. How many ways can 7 out of 15 patients with the same illness be randomly selected to receive an experimental drug?
4. How many different ways can 5 out of 8 different shirts, 4 out of 10 different pairs of slacks, and 3 out of 6 different ties be selected?