Since he was born, Joel's grandmother sent him $100 on his birthday. His parents encouraged him to save the money every year in an account
that paid 3% interest annually. On his 10th birthday, he calculated
he would have $1,000 plus the interest which he calculated to be $30.00
(3% of $100 every year). But when the bank statement arrived
his balance was $150 more than he expected!
Which statement describes why he had accumulated more than expected?