When an ice cube is placed on a metal block at room temperature (30°C), the heat transfer occurs due to the temperature difference between the ice and the metal block. The metal block is at a higher temperature than the ice cube.
The correct statement would be: Heat is transferred from the metal block to the ice cube, and the ice melts.
This process occurs because heat naturally flows from the warmer object (the metal block) to the cooler object (the ice cube). The heat absorbed by the ice cube leads to its melting.
In your scenario with two rooms at 50 degrees and 80 degrees separated by a closed door, the heat transfer dynamics would not directly affect the statement about the ice cube and the metal block unless the air temperature of the room with the ice cube was relevant. However, since the ice melts due to the heat from the metal block, the primary statement would still be focused on the heat transfer between those two.