While enjoying a fun afternoon sailing on the most lovely lake in the kingdom a spoilt princess realises she has lost a diamond and pearl earing in the water. The princess is extremely upset by the this and implores her father, the king, to do something about it immediately.
The king decides to drain the lake. His engineers tell him that there are three pipes available to do the job. The first will drain the lake in 8 days, the second in 12 days and the third in 24 days. How long will it take to drain the lake if the king uses all 3 pipes at once?
You can find the answer here.
2 comment(s):
4 days.... now I'll go check the answer.
Yippee! I was never much good with numbers at school. I'll imagine some readers see the answer in their heads before they finish reading the question. I had to apply so many braincells to it that my kidneys stopped working for thirty seconds.
But at least my plodding method worked.
Now we have to ask just how well filtered are those pipes. Isn't there a serious risk the ear-ring will be flushed out with the water. Even if not, there'll be a prodigious quantity of mud and dead fish to sift through.
The King should just tell his daughter to take up scuba-diving or just learn the lesson that ear-rings and boating are a bad mix.
Simpler than their explanation is to note that the first pipe drains 1/8 of the lake per day, the second 1/12, the third 1/24. 1/8 + 1/12 + 1/24 is 1/4, so it takes 4 days.
Post a Comment