It takes 14 hours for a faucet with a flow of 18 liters per minute to fill a reservoir with water. How long will it take if its flow is reduced to 7 liters per minute?

Sure, here's how you can solve this problem:

1. First, find out how much water the reservoir can hold. You can do this by multiplying the flow rate of the faucet by the time it takes to fill the reservoir. In this case, the flow rate is 18 liters per minute and the time is 14 hours. But since the time is given in hours, you need to convert it to minutes because the flow rate is in liters per minute. There are 60 minutes in an hour, so 14 hours is 14 * 60 = 840 minutes.

2. Multiply the flow rate by the time to find the volume of the reservoir: 18 liters/minute * 840 minutes = 15120 liters.

3. Now, find out how long it will take to fill the reservoir with a flow rate of 7 liters per minute. You can do this by dividing the volume of the reservoir by the new flow rate: 15120 liters / 7 liters/minute = 2160 minutes.

4. Finally, convert the time from minutes back to hours by dividing by 60: 2160 minutes / 60 = 36 hours.

So, it will take 36 hours to fill the reservoir if the flow rate is reduced to 7 liters per minute.