At the beginning of each year for 10 years, e4,800 is deposited in a savings account which pays a certain fixed rate of interest per annum. At the time of the last payment, the proceeds of the account are used to purchase a level annuity payable annually in arrears for 15 years at the same fixed rate of interest as that paid on the savings account. If the annuity instalment is e5,500, find the rate of interest payable on the savings account.