Application of Exponential Functions GROWTH AND DECAY 1. A rare coin is bought at an antique auction in 1998 for $500. Each year, its value appreciates by 6% of its purchase price. Determine the coin's value in 2010. The equation below represents this, where : is the time in years and y is the new price of the coin. 55(1 + 0.06] 2 An isotope of sodium, Na-24, has a half-life of 15 h. If a sample contains 45 g of Na-24. find the amount remaining after 5 days has passed. The equation below represents this, where t is the time, in hours, and M is the new mass. (HINT: there are 24 hours in 1 day) M - 45 (7) 3. A car cost $32 600 in the year 2001. By 2007. it is worth $12 295. By what percent did the car depreciate (decking in value) per year