(a)[2]
Sofia puts $400 into a savings account. This account pays simple interest at 2.8% per year. Calculate the total amount of interest Sofia receives after 3 years.
(b)[1]
Luis places $400$ in another savings account that also pays simple interest. The interest rate on this account is 0.4% per year higher than the rate in Sofia’s account. Calculate how much more interest Luis receives each year than Sofia receives each year.