Final answer:
It will take 30 hours to fill the reservoir at a rate of 60 liters per minute.
Step-by-step explanation:
To find the number of hours it will take to fill the reservoir, we need to convert the volume of the reservoir to liters, since the rate at which water is pouring in is given in liters per minute. 108 m³ is equal to 108,000,000 liters. If water is pouring in at a rate of 60 liters per minute, then it will take 108,000,000/60 = 1,800,000 minutes to fill the reservoir. Convert this to hours by dividing by 60, giving us 1,800,000/60 = 30,000 hours. So the answer is Option A 30 hours.