Calculate `theta_(1)` and `theta_(2)` in shown situation.

Answer

`theta_(1) = 116^(@)C , theta_(2) = 74^(@)C`

Explanation

In steady state rate of flow of heat in the whole system will be same .
`(KA(200-theta_(1)))/(l) = (2KA(theta_(1) - theta_(2)))/(l) = (15KA(theta_(2)-18))/(l)`
`implies 200- theta_(1) = 2theta_(1) - 2theta_(2)` & `2theta_(1) - 2 theta_(2) = 1.5theta_(2) - 27`
`implies theta_(1) = 116^(@)C , theta_(2) = 74^(@)C`