Roman the Tavernmaster has $20 worth of gold coins. He sells 3 gold coins to Dorothy. After she pays him, he has $12. How many gold coins does Roman have left?
Thoughts? Step-by-step reasoning:
Dorothy paid $12 for 3 gold coins so each gold coin is worth $12 / 3 = $4. The Tavern master originally had $20 worth of gold coins which is $20 / $4 = 5 gold coins. He gave 3 out of 5 gold coins to Dorothy so he now has 5 - 3 = 2 gold coins left.
Thus, the answer is 2.