For the composite wall idealized by the one$-$dimensional model shown in Figure P$13-7,$ determine the interface temperatures. For element $1,$ let $K_{}=5\frac{W}{m*C}$; for element $2,K_{}=10\frac{W}{m*C}$; and for element $3,K_{}=15\frac{W}{m*C}.$ The left end has a constant temperature of $200C$ and the right end has a constant temperature of $600C.$