£13,000 was deposited in a savings account that pays simple interest. After 15 years, the account contains £19,825. Work out the annual interest rate of the account. Give your answer as a percentage (%) to 1 d.p. £ 13,000 was deposited in a savings account that pays simple interest . After 15 years , the account contains £ 19,825 . Work out the annual interest rate of the account . Give your answer as a percentage ( % ) to 1 d.p.​