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Quickie

Posted: 11 Jul 2018, 15:50
by johnh
Spotted this in a business article, puzzle set by an economist.

Imagine you are in a waterproofed football stadium. The referee drops a single drop of water on the centre spot. One minute later he drops two spots there. Another minute later 4 drops there and so on. How long would it be before the stadium was full of water and everyone drowned?


(clue - after 45 minutes the stadium is 7% full.)


PS I know this can't be 'worked out' but requires 'best guesses'.

PPS Don't ask me how he worked it out. After all, he is an economist! :shock:

Re: Quickie

Posted: 11 Jul 2018, 16:11
by MOT1964
I think it's 49 minutes, although I could be wrong because A Level Maths is now a distant memory for me ........ :?

Re: Quickie

Posted: 11 Jul 2018, 16:22
by Sniffer
Who'd be daft enough to stay in the stadium if you could see you were going to drown?

Re: Quickie

Posted: 11 Jul 2018, 16:57
by Selby White
MOT1964 wrote:I think it's 49 minutes, although I could be wrong because A Level Maths is now a distant memory for me ........ :?
Agree with that except it would be 112% full :shock:

Re: Quickie

Posted: 11 Jul 2018, 17:47
by kk white
Isn't it an exponential growth question? Just because you double the drops, doesnt mean you double the percentage...

Re: Quickie

Posted: 12 Jul 2018, 11:20
by johnh
MOT1964 wrote:I think it's 49 minutes, although I could be wrong because A Level Maths is now a distant memory for me ........ :?

49 minutes is right. Well done MOT1964. :clap:

Re: Quickie

Posted: 12 Jul 2018, 14:40
by MOT1964
johnh wrote:
MOT1964 wrote:I think it's 49 minutes, although I could be wrong because A Level Maths is now a distant memory for me ........ :?

49 minutes is right. Well done MOT1964. :clap:
Cheers johnh :thumbup:

Re: Quickie

Posted: 14 Jul 2018, 14:51
by Davycc
Ahem... can we let the water out yet, we've a game on later?

Re: Quickie

Posted: 14 Jul 2018, 16:02
by johnh
Davycc wrote:Ahem... can we let the water out yet, we've a game on later?
No point, your game would be rained off anyway. :D

Re: Quickie

Posted: 14 Jul 2018, 17:52
by Davycc
johnh wrote:
Davycc wrote:Ahem... can we let the water out yet, we've a game on later?
No point, your game would be rained off anyway. :D
Fair point John, fair point :D