nina can ride her bike 63,000 in 3,400 seconds, and sophia can ride her bike 10 miles in 1 hour. what is ninsas rate in miles per hour if there are 5,280 feet in a mile?

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?