Incoming logic:
Okay, pretend you have a ten foot piece of wood and you want to have two equal pieces of wood that measured three feet each. It takes five minutes to make the first three foot piece of wood, and another five minutes to make the second piece of three foot wood. If the questioned ask how long it would take to make a third piece of wood it would be fifteen minutes. Again, a ten foot piece of wood can be cut three times if you wanted three equal length three foot pieces.