Question

A spoonful of cream is taken from a pitcher of cream and put into a cup of coffee. The coffee is stirred. Then a spoonful of this mixture is put into the pitcher of cream. Is there now more cream in the coffee cup or more coffee in the pitcher of cream.
The answer is the same amount but is there anyway to solve it mathematically??

Answer 1

Of course. There's ALWAYS a way to solve it mathematically.

Say there's x ounces of cream in the pitcher and y ounces of coffee in the cup. We take one spoonful (say z ounces) of cream, put it into the coffee. Now there's x-z ounces of cream in the pitcher and still y ounces of coffee in the cup (and z ounces of cream in it for y+z total ounces). Then we take a spoonful of coffee plus cream (we assume the spoonful is half coffee and half cream) and add it to the cream pitcher (z/2 ounces of coffee and z/2 ounces of cream in the spoonful). Now there's z/2 ounces of coffee in the cream pitcher. Since we had z ounces of cream in the coffee cup and took out z/2 ounces, we now have z/2 ounces of cream in the coffee cup. Hence, they're the same. Make sense?

Again, this assumes that the spoonful of the mixture contained equal amounts coffee and cream.