Annuity
Used for estimating returns on periodic investments in mutual funds etc.
If paid at the start of period,
A = P*[{(1+i)^n โ 1 }/i]*(1+i)
If paid at the end of period,
A = P*[{(1+i)^n โ 1 }/i]
A = Final amount
P = Installment each time
n = Total number of installments
i = Rate (in %) for period