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Question 8 (15 points) Ralph knows that he is going to have to replace his roof soon. If he has the roof replaced now, it will cost $10,000. He could wait 5 years, but it will then cost him $20,000. At what rate will these options cost the same. (Hint: This is also known as the break-even point. Exact calculation up to two decimals is not difficult. If stuck, trial and error will help. (No more than two decimals in the percentage interest rate but do not enter the % sign.) Answer for Question 8
In order to find at what interest the options will be equal we must calculate at what rate money doubles after five years, so we must do:
20.000$ 5 = 2 = 1,1487 10.000$ 1,1487 − 1 = 0,1487
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14,87% The interest rate at which the options will be equal is 14,87€.