Final answer:
According to the CDC, you should scrub your hands together in a lather for at least 20 seconds when washing them.
Step-by-step explanation:
According to the Centers for Disease Control and Prevention (CDC), you should scrub your hands together in a lather for at least 20 seconds when washing them. This helps to effectively remove dirt, germs, and bacteria from your hands.
An easy way to remember how long to wash your hands is to hum the "Happy Birthday" song from beginning to end twice. This will ensure that you are washing your hands for the recommended amount of time.