A car dealership sells used cars for 7000 which one and new cars for 16,000 if a total of 17 cars were sold for 191,000 how many of the car so used

9 were used, 8 were new. Trial and error, starting at 16x17 and working your way down. You can add the extra zeroes for the thousands later, and the seventeen is specified as that amount of cars were sold.