Life Situation 3: On a Budget
All 3 shops are also having discounts. In Shop A you get 20% off on everything. In Shop B for every item you buy you get one more for free. In Shop C the only discount is that you can get 1 pencil, 1 eraser, 1 pen and 1 ruler for only $6.
You can buy more than what you need if it saves more money than just what you need. If you do not use the discount deal in the shops you buy them for normal price.
If you only have time to go to one shop, and want to use as little money as possible to buy everything you need, which shop should you go to?