As is often the case after a hard day of Quiz question writing in Quiz Master Shop Towers, we had strolled down to The Jolly Quizmaster for a restorative drink or two. As you can imagine, we are on good terms with the landlord who, after we had bought our first round, presented us with two glasses and a question.
The two glasses in question held whisky and water. In fact one glass held just whisky (a fine single malt, to boot) and the other held just water, and the two glasses both held exactly the same amount of its respective liquid.
The landlord took out a teaspoon and ladled a small number of teaspoons of water into the glass of whisky. He then reversed the process, ladling the same number of teaspoons of the whisky and water mixture into the glass of water.
He placed the two glasses of drink in front of us and said that we could have them if we could tell him if which glass held the strongest mix. That is, was there now more water in the whisky glass than whisky in the water glass, or was there more whisky in the water glass than water in the whisky glass?
So, what is the answer? Would you get a free drink in The Jolly Quizmaster?
In fact, neither is the case, and both glasses are equally diluted.
There were equal amounts of whisky and water to start with, and this has not altered as no water or whisky has been added or removed. The two glasses contain the same amounts of liquid (the same amount of liquid was moved one direction and then back), and so there must be exactly the same amount of water in the whisky glass as whisky in the water glass.