$T_i=20C=293\mathrm{.}15K,$

$k_1=0\mathrm{.}87\frac{w}{m}k$

k$2=0\mathrm{.}52,$ k$3=0\mathrm{.}87$

$T_0=-6C=267\mathrm{.}15k$

$h_1=8\frac{}{m^2}k$

$h_0=23\frac{w}{m^2}k$

Surface area $(A)=25m^2$

$L_1=0\mathrm{.}03m,$

$L_3=0\mathrm{.}04m$

$L_2=0\mathrm{.}19m,$

$L_{\text{i}\text{n}\text{s}}=?$

$k_2=0\mathrm{.}52\frac{w}{m}k$

a$)$ Find heat transfer for a surfoce of $25m^2?$

b$)$ Find the thickness of the insulation. $($kins $(=0\mathrm{.}04\frac{w}{mk}$