This question has options. How would someone go about accomplishing this goal?
How to test if a toilet is running.

Select from:
- Drop some food scraps into the tank. Wait a few minutes. If you see the food scraps flowing into the bowl, take a trip to your local hardware store to pick up a new flapper..
- Drop some food coloring into the tank. Wait a few minutes. If you see the food coloring bleeding into the bowl, take a trip to your local hardware store to pick up a new flapper..
Drop some food coloring into the tank. Wait a few minutes. If you see the food coloring bleeding into the bowl, take a trip to your local hardware store to pick up a new flapper.