Jan Green established a savings account for her son's college education by making annual deposits of $6,000 at the beginning of each of six years to a savings account paying 8%. At the end of the sixth year, the account balance was transferred to a bank paying 10%, and annual deposits of $8,000 were made at the end of each year from the seventh through the tenth year. What was the account balance at the end of the tenth year?

Note: the formula needed and explanation.