3. Hoarding Tokens
You were told that the TTC is going to increase its fare from $2.90 to $3.00, effective on January 1, 2017. As a result, you would like to buy some tokens (at $2.90) and save them for future use in 2017. However, there are rules on the purchase and use of tokens. Assume that (1) tokens can only be purchased for personal consumption but not for resale, and you use 2 tokens every day, (2) you can buy at most 10 tokens a day, but since you need to use 2 tokens a day, the maximum number of tokens that you can hoard is 8 per day. Suppose the annually compounded interest rate is 10%/year. When should you start hoarding tokens?