Answer:
59.5 months
Step-by-step explanation:
initial investment x (1 + appreciation rate)ⁿ = initial investment + $100,000 + ($400 x n)
$220,000 x (1 + 0.75%)ⁿ = $320,000 + $400n
1.0075ⁿ = $320,000/$220,000 + $400n/$220,000
1.0075ⁿ = 1.4545 + 0.001818n
I tried to solve it by trial and error:
50 months:
1.453 ≠ 1.5454
60 months:
1.566 ≈ 1.564 ⇒ Almost
61 months:
1.577 ≠ 1.565
59 months:
1.554 ≈ 1.562 ⇒ Almost
59.5 months:
1.56 = 1.56