The Galindo family plans to start a small business in our neighborhood. The father borrows $10,000 from the bank at an annual interest rate of 7.5% rate for 42 months. What is the amount of interest he will pay on this loan?(worth 80 points)

Abank manager wants to encourage new customers to open accounts with principals of at least $2 comma 500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?