A logic / mathematical diversion

[alfabit]

Try again

This is for NASA job interview ? I read they hire astronauts !!

[Mjolinor]

This is for NASA job interview ? I read they hire astronauts !!

This is from a Cambridge entrance interview.

[cunny]

Light candle 1. Let it burn for approx a quater.
Light candle 2
When candle 2 has burnt approx half way down.
Turn candle 1 upside down.
That was my guess

Been thinkin about this, turn the candles on thier side, place half way on each other, light both ends at same time?

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Or summet like that

[gc1966]

right oh,here goes

get on the motorway (in your car obviously)

set cruise control at 60 mph

zero odometer and light candle at same time

drive for 45 miles to mj,s house and lob lit candle thru letterbox

simples

[RedSpider]

why? what's happening in 45 minutes?

[gc1966]

it gets 15 minutes to burn the ~~~~ers house down for causing me brain to hurt .

[flyingpig]

Try again

So in all honesty please tell me why this would not work?

If the candle - regarldess of burning speed - will last for 60 minutes. If yuu light it at both ends it will expire in 30 minutes.

Break the other candle in half. If you have half a candle - it will burn for 30 mins. So light that at both ends and after 15 minutes it will be 45 mins..??

Thanks.

FP

[Shady]

no, cos he said in original post, that it doesnt burn at set speed, it COULD take 10 minutes to burn halfway and then 50 minutes to burn the other half.

[barrowmanandrew]

light first candles at both ends, it should taker half an hour to burn.

then half the second candle and light both halfs at each end it should take 15 minutes for it to burn.

gives ya 45minutes..

[Larue]

Can't get my head over this....have tried without success.
May be it's worth just enjoy burning candles without counting?
It's Saturday evening....let's relax and enjoy some burning candles,ale,family....

[Snowy79]

Lighting the candle at both ends will not work as has been said before. It could take the first side 3 minutes to burn out and the other half 57 mins.

[barrowmanandrew]

Lighting the candle at both ends will not work as has been said before. It could take the first side 3 minutes to burn out and the other half 57 mins.

thats the key m8.

one candle takes an hour to burn,
so if its lit at both ends it will burn twice as fast.

one end might burn quicker than the other but it doesn't matter because candle will be completly burned in half an hour.

same principal applies when candle is split in two and burned at both ends, candle will burn 4x as fast,
one half may be brned quicker than other, but again it doesnt matter.

[Shady]

ive got electricity.


~~~~ candles

[Snowy79]

I know the text book answer but it is incorrect if it burns as I described above.

[Snowy79]

How does spliting a candle and lighting it at both ends make it burn out in 30 mins. If the candle is 6 inches long and you split it in half you end up with 2 x 3 inches. If you light them both and one burns out in 3 minutes as I've said above and the other half burns out in 57 minutes where do you get the 30 minutes from?