For #2 on the mock test, use K = QH/W. This should be used whenever you are dealing with a heater or heat pump. If you are dealing with a refrigerator, use K = QL/W.
Sorry for the late worked out solution for Day 3 and 4 but better late than never. Here is the link to the worked out problems expect the same style of worked out problems tomorrow for the Mock Test.
HAPPY STUDYING FELLOW SENIORS!!