After much trial and error, we have reached a conclusion that the temperature at which the hot water is at, affects the experiment. Hence, some of our experiments produced the correct results while others did not.
Another reason why our experiment could not work out right is because, certain conditions were not met. Thus the correct results could not be produced.
All in all, through our results and analysis, we have concluded that hot water does not always freeze faster than cold water unless certain conditions are met. but we managed to get the results in the end.
I feel that we should have been more committed to doing the experiment... and be more focused.
Given more time, we would investigate further with more test tubes with water at varying temperatures, as well as try to understand this down to the molecular level if possible.