The total amount of money in the account at the first year.

The simple interest formula is .

                  (Substitute )

                                   (Multiply: )

                   (Add the amount invested and the interest)

At the end of the first year, $504 in the account.

The total amount of money in the account at the second year.

The simple interest formula is .

                   (Substitute )

                                (Multiply: )

             (Add the amount invested and the interest)

At the end of the second year, $529.2 in the account.

The total amount of money in the account at the third year.

The simple interest formula is .

                 (Substitute )

                                (Multiply: )

The amount in the account after 3 years is $504 + $25.2 + $26.46 or $555.66 \ \

The total amount of money is $555.66.