Consider the question. If you buy a dozen of doughnuts, it costs $8; but if you buy 2 dozens, it costs $14. How much will you save from buying 3 sets of 2 dozens than buying 6 sets of 1 dozen?
 What is the step-by-step reasoning process to arrive at the answer: 6?
Six sets of 1 dozen of doughnuts cost $8 x 6 = $48. Three sets of 2 dozens of doughnuts cost $14 x 3 = $42. Therefore, you can save $48 - $42 = $6.