# IGGY

### The donkey was carrying five sacks and the mule was carrying seven!

Suppose the donkey carries $x$ sacks and the mule $y$. Then the mule tells us two things;

$Y+1=2 (x-1)$

$X+1=y-1$

The second equation tells us that $y=x+2$. Now the first equation tells us that $x+3=2x-2$, which implies that $x=5$.

So $y=7$.

As seen on page 224, Professor Stewart's Hoard of Mathematical Treasures