Amicrowave is placed on top of two boxes. one box is 3 feet 11 inches tall, the other box is feet inches tall, and the microwave is 4 feet 8 inches tall. how tall are they combined?

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! "?