Low carbon steel is expose to carbonizing atmosphere for 1 hour, the exposure is done at high temperatures so the surface concentration of carbon is 0.60% by weight and the diffusion coefficient of carbon in the steel is 1.0 x 10-11 m2/s. If the low carbon steel initial has 0.15% by weight of carbon, what would be the concentration of carbon at 0.02 cm after 1 hr of exposure