Please help with this

If i purchase a product for $79.99 and two accessories for 9.99 and 7.00 how much will i owe after taxes applies 8.75%

Me with this assignment ! i only partially understand, so explain. also it's a work sample. at the championship bike race, steve and paula were fighting for first place. steve was 175 feet ahead of paula and had only 300 feet left to go. he was very tired and was going only 9 feet per second. paula was desperate to catch up and was going 15 feet per second. who won the bike race and by how far did she/he win?

The base of the rectangle pyramid is 13 inches long and 12 inches wide the height of the pyramid is 18 inches . what is the volume of the pyramid ?