Four thin identical rods `AB, AC, BD` and `EF` made of the same material are joined as shown. The free-ends `C,D` and `F` are maintained at temperature `T_(1),T_(2)` and `T_(3)` respectively. Assuming that there is no loss of heat of the surroundings, the temperature at joint `E` when the steady state is attained is `(1)/(K) (2T_(1)+2T_(2)+3T_(3))`. Find `K (E` is mid point of `AB)`