BrainDen.com - Brain Teasers

# Reservoir

## 32 posts in this topic

I probably just don't get this, but how do you fill up a resevoir with four taps that empty it??

##### Share on other sites
I probably just don't get this, but how do you fill up a resevoir with four taps that empty it??

The taps are used to fill the reservoir, not empty it. The taps get their water from another source.

##### Share on other sites

without a size or volume or an amount equal to full i cant really understand this one, but i know that it will be less than six hours. due to the fact that the last one can do it in 6hrs the others are also adding water at the same time constantly making the amount that is empty smaller as the full amount in six hours is being assisted by the slower faucets or spigots. i think i spelled spiggotts right. lol

##### Share on other sites

8 days 6 hrs to fill up :melow:

##### Share on other sites

The answer is as found by many, 4.72 hours. But I'm wondering how anyone could come up with an result greater than 6 hours. Unable to do the math, understandable, but such a failure of logic, that's bewildering. Misreading the question?

##### Share on other sites

As tap 4 can fill the entire reservoir in 6 hours, the four of them together will definitely fill it in less than that. I found an answer close to everyone else's but went about it by using a random value for the capacity of the reservoir. To avoid making my numbers complicated I used 288 gal (the LCM of 48, 72, 96, and 6). Then I found the rate of flow for each tap and added them to find that, together they would fill the reservoir at a rate of 61 gal/hr.

288/61 gives you 4 hours, 43 minutes, 17 seconds, and 7/61 of a second.

##### Share on other sites

In solving this, I got the total number of hoursthe four faucets can fill 4 pools. I got the answer 220 hours, and divided it to four.... I got 55 hours or 2 days and 7 minutes... I don't know if this is correct, but at least I get the chance to express my point of view...

WAHH!!! I don't know what have overcame me that I used my old system of computation to get my hypothesized answer.... I can't believe it! I'm still quite a child anyway...