Can someone plz help me understand this

If i have 20$ and i gave 5$ away how much i got

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500

Consider an example of a deck of 52 cards: example set of 52 playing cards: 13 of each suit clubs, diamonds, hearts, and spades ace 2 3 4 5 6 7 8 9 10 jack queen king clubs diamonds hearts spades what is the probability of drawing three queens from a standard deck of cards, given that the first card drawn was a queen? assume that the cards are not replaced.