Can anyone help me please

Charlie is at an amusement park that has 18 different rides. each ride costs $1.75. the function c(r) = 1.75r represents the total amount of money that charlie will spend if he goes on r rides, but he never goes on the same one more than once. what domain and range are reasonable for the function?

If f(x)=3 over x+2 - square root x-3 then f(7)=

You draw a card at random from a deck that contains 33 black cards and 77 red cards.