An equation for the depreciation of a car is given by y = a(1 – r)t , where y = current value of the car, a = original cost, r = rate of depreciation, and t = time, in years. the value of a car is half what it originally cost. the rate of depreciation is 10%. approximately how old is the car? a)3.3 years b)5.0 years c)5.6 years d)6.6 years