Paradox or Riddle. Brain-training exercises.

He who is not a magnet can be magnetized with a magnet.

You seem to be the closest. Anyway, this is a tough one, and I didn't know the answer myself. I found it in some book, but I don't remember which one. A magnet has its maximum magnetic field strength at its poles. As you move towards the center of the magnet, the magnetism weakens, and at the very center, its value is zero. Therefore, if in a "T-shaped" connection, the bars stick together, and the magnet is the bar that touches its end face.

Added 43 minutes later
Imagine one disabled person has $12.50, and another (also disabled) has $12.50. They decide to pool their money and buy boots for $25. When they buy them, the store owner feels sorry for the disabled people and tells the saleswoman to give them a $3 discount. On the way to the disabled people, the saleswoman puts $1 in her pocket and gives the rest ($2) to the disabled people ( $1 to each). In the end, with the discount, they bought the boots for $23, and the saleswoman has $1 in her pocket, totaling $24... where is the other dollar??
Is it a paradox or a riddle? If it's a paradox, explain it; if it's a riddle, solve it.