Dividing whole numbers if insulation can be installed at a rate of 1,400 square feet per hour and 29,400 square feet needs to be installed, how many hours will the job take?

Dakota earned $7.50 in interest in account a and $18.75 in interest in account b after 15 months. if the simple interest rate is 4% for account a and 5% for account b, which account has the greater principal? explain. to make it a little easier, there is an image. good luck!