The formua for determining simple interest interest is expressed as
I = PRT/100
where
I = interest
P = principal or initial amount
R = interest rate
T = number of years
From the information given,
P = 215
T = 8
R = 8
I = (215 x 8 x 8)/100 = 137.6
The ending balance after 8 years = principal + intereest
Ending balance = 215 + 137.6 = $352.6