SOLUTION: The cost of tires is $60.00 each with a 30% discount for 6 pairs or more. How much would it cost to replace the tires on 5 cars ( not including spares)

The cost of tires is $60.00 each with a 30% 
discount for 6 pairs or more. How much would 
it cost to replace the tires on 5 cars (not 
including spares)

First multiply $60.00 by 12, because 6 pairs 
means 6×2 or 12 tires.

             $60.00
               × 12
             120 00
             600 00
            $720.00     


Now multiply $720.00 by 30% to get the dollar 
discount.  But first you must change 30% to a 
decimal by moving the invisible decimal two 
places left and removing the % sign, getting 
.30.  You can also drop the 0 on the end of
.30 for multiplying, and just use .3 :

             $720.00
                × .3
             $216.00

Now subtract the $216.00 discount from the
$720.00 to get the final cost:

             $720.00
            - 216.00
             $504.00

Edwin