In the first hour and a half all the generators worked and produced (14+14+18)×1.5=69 liters. In the next two hours two generators worked and produced (14+18)×2=64 liters. The rest of the time 5−1.5−2=1.5 hours only one generator worked and produced 14×1.5=21 liters of foam. The total amount of foam that was created is 69+32+21=154 liters.