Rebecca is currently working, but is planning to start a college in few years. For this purpose, she would need $20,000. Today she can start investing $750 monthly in an investment account that pays 6 percent compounded monthly. How long would it take her to have enough money to start college?

It will take 25 years her to have enough money to start college.

Explanation:

Use Annuity future value To calculate the period.

AFV = P [ (((1 + i) ^n) - 1) / i]

$20,000 = $750 [ (((1 + 0.06) ^n) - 1) / 0.06 ]

($20,000 x 0.06) / 750 = (1.06) ^n) - 1

1.6 = 1.06^n

log 1.6 = n log 1.06

n = log 1.6 / log 1.06

n = 25 years

So, It will take 25 years her to have enough money to start college.