How to solve

Mr$.$ Jones bought a lot for $$5000$ with a down payment of $$500.$ He agreed to pay $6\%$ simple interest

on the balance. If he paid $$2000$ three months after purchase and $$1500$ six months later, what

payment $1$ year after the date of purchase will discharge his obligalion? Put the focal date at the

end of $1$ year.

Given the linear series

Find the sum to first $n$ terms