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Required information

Consider a $20-$cm$-$thick large concrete plane wall $(k=0\mathrm{.}77\frac{W}{m}*K$ subjected to

convection on both sides with $T_1=27C$ and $h_1=10\frac{W}{m^2}*K$ on the inside, and $T_{{}_2}=$

$8C$ and $h_2=12\frac{W}{m^2}*K$ on the outside.

Assuming constant thermal conductivity with no heat generation and negligible radiation, evaluate the

temperature at the outer surface of the wall. $($Round your answer to a single decimal place.$)$

The temperature at the outer surface of the wall $=$