Apizza restaurant offers 21 different toppings. how many 5-topping pizzas can be created if each topping can be used only once?

Need on this one asap im almost done with this subject

The probability that you roll a two on a six-sided die is 1 6 16 . if you roll the die 60 times, how many twos can you expect to roll

Pepe and leo deposits money into their savings account at the end of the month the table shows the account balances. if there pattern of savings continue and neither earns interest nor withdraw any of the money , how will the balance compare after a very long time ?