Fincial Math question?

Question

"You deposit $2000 annually into a Roth IRA that earns 6.85% compounded annually. You stop these deposits 10 years after you set up the account. You leave the account open for 25 years after the last deposit.

How much is in the account after 35 years?"

Answer 1

After the 1st 10 years,
V = ($2,000/0.0685)[(1.0685)^10 - 1] = $27,437.89
After the next 25 years
V = $27,437.89(1.0685)^25 = $143,785.10