Original price - $82. percent of sale price - $65.60

The original price was $82.

-- The dealer knocked ($82 - $65.60) = $16.40 off of the price because
he loves his customers so much and he wanted to make their lives easier.

-- The amount he knocked off is  ( 16.40 / 82 ) = 0.2  =  20% of the original price.



Check:

If he reduced the original price 20%, then 80% of it must have been left.

80% of the original price =  0.8 x $82  =  $65.60

I hoped i help :)