In the carburization of Fe, the carbon concentration at the surface, Cs, is set at 1 wt. %. Using the Gaussian Error Function Table below, calculate how long it will take at 1000 C to reach the carbon concentration, C, of 0.6 wt.% at 1mm from the surface. The initial carbon content is 0.2 wt.% and D = 3 x 10-11 M/s