Calculate the amount of money​ you'll have at the end of the indicated time period.

Question

You invest ​$4000 in an account that pays simple interest of 7​% for 30 years.

Answer 1

It would be silly to put money in an account for 30 years at simple interest, but....
if you insist:
amount = 4000 + 4000(30)(.07) = 12,400

Now, if you had done so at compound interest ....
amount = 4000(1.07)^30 = 30,449