One half of the sum of a number and 10

You just purchased two coins at a price of $670 each. because one of the coins is more collectible, you believe that its value will increase at a rate of 7.1 percent per year, while you believe the second coin will only increase at 6.5 percent per year. if you are correct, how much more will the first coin be worth in 15 years?

What is 0.000008 meters in scientific notation

You eat $0.85 for every cup of hot chocolate you sell. how many cups do you need to sell to earn $55.25