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ENGAGE THOSE BRAINS, folks: we have a teasing question for you.
Each afternoon this week, we’ll be setting you a (not too) tough riddle to get the cogs whirring and test your mathematical mettle.
If this prospect fills you with either a. joy, or b. dread, the mathsweek.ie site is worth a look – with events for maths fans and for those who might feel the need to brush up on their numeracy skills. The events are running from now until Sunday.
Thursday’s puzzle:
I realised that I take around 60 seconds to brush my teeth and I’m in the habit of leaving the tap running. I measured that the tap will fill a 2-litre jug in 16 seconds. I decided to just allow the water to flow while I was rinsing the brush and my mouth. I could accomplish this in 10 seconds.
Assuming that I brush my teeth twice a day at home, how much water will I save in a year?
All answers will be revealed tomorrow afternoon. You’ll see what other readers are thinking when you make your choice above and the pie chart shows the most popular option. (We’re not saying that the most popular will be the right one!)
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Is it a leap year?
Was that question sent in from the taoiseach’s dept. by any chance?
If I don’t pay my water charges twice how much will I save in year?
It depends…. 2 litres in 16 seconds is some serious water pressure. If they reduce the pressure on you then that rate would change. Of course, the real question is “how are they going to manage this f*cking mess?” seeing as nobody seems to really have looked at charging for water beyond shrugging and setting a pulled-out-of-the-air price…
I think that the weirdos who let taps run are the same people that leave the top off the toothpaste tube, the lights on, wet towels on the floor and other irritating habits. They don’t think.
Y’all know you’re supposed to spend at least twice that long brushing your teeth according to the dentists, right?
So in Math Day Quiz Part Two, how much money do we lose overall when you subtract the cost of the dental work from the money saved by not running the tap for more than ten seconds?
Are those my feet!?
16 seconds= 2 litres
60/16=3.75 x 2 litres is 5,475 litres annual usage
10 seconds usage = 10/16×100/1=62.5%
62.5% of 2 litres is 1.25 litres
1.25 x 2 x 365= 912.5 new usage
SAVING 5475-912.5= 4,562.50 Litres
Is this water fluoridated btw??!
Did that one in my head.
Hold on, I know I have a medal around here somewhere…
Someone knows their 365 times tables so.
*Gag* Why have a photo of spit and foam?
*Shudders*
POSSIBLE SPOILERS (that’s if I got this right :) )
2 litres in 16 seconds is .125 litres a second. That’s 7.5 litres in the 60 seconds he normally left it on. But now he uses only 10 seconds worth (1.250 litres) so his saving is 6.25 litres twice a day = 12.5 litres…. do that 365 days of the year (presuming its not a leap year!) and that’s well…. I’ll leave you to do the maths on that bit :)
The question doesn’t make clear on what terms you are saving the water? It just tells us it takes 70 seconds for him to brush his teeth and rinse his mouth and brush.
If you only brush for 16 seconds twice a day you’ll spend a hell of a lot more on dental work than you will on water charges!
have your say