Sanderson Manufacturing makes paint-brushes and other paint supplies. The 3 paint- brush has a standard of 0.28 pounds of bristles, and one pound of bristles costs Sanderson $3.45 to purchase. In March, Sanderson made 12,000 3"paint-brushes and used 3,400 pounds of bristles. This cost the company $11.730. What was the difference in the number of pounds of bristles Sanderson should have used compared to the number of pounds they actually used? They used 40 pounds more than they should have. O They used 138 pounds less than they should have. O They used 138 pounds more than they should have. O They used 40 pounds less than they should have