Three rods of same dimensions have thermal conductivities 3K,2K and K. They are arranged as shown in the figure below:

Question

$(1)\;\large\frac{200}{3} ^{\circ}C\qquad(2)\;\large\frac{100}{3} ^{\circ}C\qquad(3)\;75 ^{\circ}C\qquad(4)\;\large\frac{50}{3} ^{\circ}C$