If you can invest $200,000 at a 10.5% annual rate, compounded monthly, how long will it take to have $500,000? (Do not your intermediate calculations. Round your final answer to the nearest whole month.)

Use Future value formula for the calculation of number of years

Future Value = Present value (1 + interest rate) ^number of years

FV = PV (1 + r) ^n

$500,000 = $200,000 (1 + 10.5%) ^n

$500,000 / $200,000 = (1 + 0.105) ^n

2.5 = (1.105) ^n

log 2.5 = n log 1.105

n = log 2.5 / log 1.105

n = 9.1771

n = 9 years 2 months