A cook went to a market to buy some eggs and paid $12. But since the eggs were quite small, he talked the seller into adding two more eggs, free of charge. As the two eggs were added, the price per dozen went down by a dollar. How many eggs did the cook bring home from the market? Choose the most appropriate option: A) 8 B) 12 C) 15 D) 16 E) 18
Say the # of eggs the cook originally got was x;   he price per egg then would be 12x and the price per dozen would be 12∗12/x.   Now, since the cook talked the seller into adding two more eggs then he finally got x+2 eggs (notice that x+2 is exactly what we should find);   So, the price per egg became 12/x+2 and the price per dozen became 12∗12/x+2 .   As after this the price per dozen went down by a dollar then 12∗12/x−12∗12/x+2=1, which simplifies to 144/x−144/x+2=1. At this point it's better to substitute the values from answer choices rather than to solve for x. Answer choices E fits: if x+2=18 then 144/16−144/18=9−8=1 .   Answer: 18
<result>E</result>
A cook went to a market to buy some eggs and paid $12. But since the eggs were quite small, he talked the seller into adding two more eggs, free of charge. As the two eggs were added, the price per dozen went down by a dollar. How many eggs did the cook bring home from the market?