The call signs of radio and television stations in the United States generally begin with the letter W east of the Mississippi River and the letter K west of the Mississippi…

The call signs of radio and television stations in the United States generally begin with the letter W east of the Mississippi River and the letter K west of the Mississippi. Repetition of letters is allowed. How many different call signs are possible if each station uses a W or K followed by 3 letters?

Renting video games from The Video Vendor costs $6 per game with no annual membership fee…

Renting video games from The Video Vendor costs
$6 per game with no annual membership fee. Renting
video games from The Game Garage costs $3 per
game, but a customer must pay an additional $60 for
an annual membership. If n represents the number of
video games a customer rents in a year, which of the
following gives all values of n for which it costs less
to rent from The Game Garage than from The Video
Vendor?

at 7am a sewage treatment tank contains 3000000 gallons of water…

at 7am a sewage treatment tank contains 3000000 gallons of water. starting at 7am, x gallons per minute flow into the tank, and y gallons per minute flow out of the tank. no water enters or leaves the tank otherwise. which of the following functions f models the number of gallons of water in the sewage treatment plant at 8am?