This problem is created by my cousin who is learning about 1-D heat transfer problems. He made this problem and made solve it with fourier's law of heat transfer with calculating thermal resistance by integrating 1/A dx, which presupposes a false assumption; if the distance away from the heat...
Thank you for noticing! As you expected, I am not native speaker and I am really really unfamiliar with English even though there was my basic foreign language education... :(