­A car dealership recently increased the average pre-tax price of its

@devashish2407Given: ­A car dealership recently increased the average pre-tax price of its cars by $2,500. As a result, a customer purchasing 18 cars at the old after-tax price can now afford to buy only 15 cars.

Asked: If the local sales tax is 8%, what is the new average after-tax price of the dealer’s cars in dollars?
Let the old pre-tax price of the car be $x.

A car dealership recently increased the average pre-tax price of its cars by $2,500. As a result, a customer purchasing 18 cars at the old after-tax price can now afford to buy only 15 cars.

New after-tax price = (x+2500)1.08 
Old after-tax price = 1.08x

18*1.08x = 15*(x+2500)*1.08
x/(x+2500) = 15/18
x/2500 = 15/3 = 5
x = 5*2500 = $12500

New average after-tax price of the dealer’s cars in dollars = (x+2500)*1.08 = $15000*1.08 = $16200

IMO D