Suppose that you are considering subscribing to Economist Analyst Today magazine. The magazine is advertising a one-year subscription for $60 or a two-year subscription for $115. You plan to keep getting the magazine for at least two years. The advertisement notes that a two-year subscription saves you $5 compared to buying two successive one-year subscriptions. If the interest rate is 10%, should you subscribe for one year or for two years? (Assume that one year from now, a one year subscription will still cost $60.)