Is this a function???

Bismuth-210 is an isotope that radioactively decays by about 13% each day, meaning 13% of the remaining bismuth-210 transforms into another atom (polonium-210 in this case) each day. if you begin with 233 mg of bismuth-210, how much remains after 8 days?

On her first stroke, maya hit a golf ball 146 yards, 2 feet, 11 inches. on her second stroke, she hit it 163 yards, 1 foot, 2 inches. how far did the ball go all together? convert the answer to larger units whenever possible.

Neal buys a board game. he pays for the board game and pays $1.54 in sales tax. the sales tax rate is 5.5%. what is the original price of the board game, before tax