Can you please explain how you solve the interest rate

On July 31, 2020, a company purchased equipment for $145,200, paying $42,000 cash and signing a 7% note payable for remainder. The interest and principal of the note are due on January 31, 2021. On July 31, 2020, a company purchased equipment for $145,200, paying $12,000 cash and signing a 7% note payable for the remainder. The interest and principal of the note are due on January 31, 2021