You have 2 different savings accounts. For Account A, the simple interest earned after 3 months is $0.90. For Account B, the simple interest earned after 18 months is $22.50. If the interest rate is 3.6%for Account A and 2.5% for Account B, how much is the principal in each account? Which account earned you the most interest the first month? Explain your answer.
Account A has a principal of $BLANK. (Round to the nearest dollar as needed.)