Today you have 100000 in your investment account which will

Today you have $100,000 in your investment account, which will grow by 7.5% annually. If you keep investing $600 every month, how many months does it take for your account balance to increase to $300,000?

Solution

Amount Invested today = $100,000
Monthly deposit = $600
Annual Interest Rate = 7.5%
Monthly Interest Rate = 0.625%
Desired Accumulation = $300,000

Let it will take ‘n’ months to have $300,000

$100,000 * FVIF(0.625%, n) + $600 * FVIFA(0.625%, n) = $300,000

Using financial calculator:
I = 0.625%
PV = 100000
PMT = 600
FV = -300000

N = 112.88

So, it will take 112.88 months to have $300,000