A flat sheet of ice (n = 1.309) has a thickness of 2.4cm. It is on top of a flat sheet of crystalline quartz (n= 1.544) that has a thickness of 1.4 cm. Light strikes the ice perpendicularly and travels during it and then through the quartz. In the time it takes the light to travel during the two sheets, how far (in cm) would it have traveled in a vacuum?