Alice has 60 marbles. Forty five are red and the rest are black. what is the ratio of the number of black marbles to the number is f red marbles? ​

Ahigh definition tv cost $800 with a down payment of 2/5 of the cost. how much is left to pay, in dollars after the down payment has been made?

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

For a function f(x), a) if f(7) = 22 then f^-1(22) = b) f^-1(f(c)) =