because when the number is negative it's lowe than a positive number and the answer "c" has the first number as a positive which that number is the greatest out of all of them in that answer
i suppose that t is an exponent. so let: v(t)=final prize of the scooter...t=time in years.....p=initial prize of the scooter . r= rate of depreciation per year so v(t)=p(1-r)^t....