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Midnight


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12 replies to this topic

#1 rookie1ja

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Posted 30 March 2007 - 03:51 PM

Midnight - Back to the Cool Math Games
If it were two hours later, it would be half as long until midnight as it would be if it were an hour later. What time is it now?

This old topic is locked since it was answered many times. You can check solution in the Spoiler below.
Pls visit New Puzzles section to see always fresh brain teasers.


Spoiler for Solution

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#2 DaVulcan

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Posted 05 July 2007 - 02:38 PM

9 PM

(1) 9 PM + 2 hrs = 11 PM or (midnight - 11 PM) = 1 hr
(2) 9 PM + 1 hr = 10 PM (midnight - 10 PM) = 2 hrs

So, (1) = 1/2 of (2)

OR straight up:

Where:
X = Solution Time
T = Midnight - X

(a) 12 - (X + 1) = T
(b.1) 12 - (X + 2) = T/2
(b.2) 24 - (2*X + 4) = T

Then:

(a) = (b.2) gives:

(c.1) 12 - (X + 1) = 24 - (2*X + 4)
(c.2) - X - 1 = 12 - 2*X - 4
(c.3) X = 12 - 3 = 9
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#3 Brookey

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Posted 07 July 2007 - 05:11 AM

I HATE number puzzles.

I never excelled at math. So that makes me an "arithmephobe." Words and punctuation were always my forte.
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#4 eyenine

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Posted 08 August 2007 - 08:04 PM

its not even a numbers puzzle...its common sense

if its 9pm... 2 hours later would be 11pm.. 1 hour later would be 10 pm... 11pm is half the distance from midnight as 10pm
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#5 sdsuman

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Posted 07 December 2007 - 06:35 PM

I got the easy answer of course, but wouldn't 10:20 pm work as well if you think of it a bit differently? One hour later is 11:20, 40 minutes away from midnight, 2 hours later would be 12:20, 20 minutes away from midnight. 20 is half of 40(for those who need the help lol)
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#6 tweak4

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Posted 11 December 2007 - 02:07 PM

I got the easy answer of course, but wouldn't 10:20 pm work as well if you think of it a bit differently? One hour later is 11:20, 40 minutes away from midnight, 2 hours later would be 12:20, 20 minutes away from midnight. 20 is half of 40(for those who need the help lol)



Except that the original puzzle states "half as long until midnight". If it were "half as far from midnight", 10:20 pm would work. However, 12:20am is a whopping 23 hours and 40 minutes from the next midnight, which throws the whole thing off...
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#7 Emapher

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Posted 01 February 2008 - 07:02 PM

why coulnt it be 8pm.
That would be 4 hours until midnight- if its two hours later- its 10pm. which is two hours until midnight.
2 hrs. is half as long as 4 hrs. so why cant this work??
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#8 rookie1ja

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Posted 01 February 2008 - 08:19 PM

why coulnt it be 8pm.
That would be 4 hours until midnight- if its two hours later- its 10pm. which is two hours until midnight.
2 hrs. is half as long as 4 hrs. so why cant this work??

wrong because:
If it were two hours later (10pm), it would be half as long until midnight (2 hours to midnight) as it would be if it were an hour later (at 9pm = remember your starting point is 8 pm = 3 hours to midnight which is not 2x2 hours).
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#9 woon

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Posted 13 March 2008 - 11:57 AM

[b]

9pm

let x = the current time.

2 hrs later = x + 2; 1 hrs later = x + 1

the statement means:

12 - (x + 1) = (1/2) {12 - (x+1)}

so 24 - 2x - 2 = 12 - x - 1

x = 24 - 2 - 12 + 1
= 9

[\b]
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#10 tara

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Posted 24 March 2008 - 08:28 AM

YES!!! for the first time ever, i managed to solve a puzzle!!!
9pm!!! 2hrs later, it'll b 11pm, ie an hour frm mdnite, n 1 hr later, it'll 10pm, ie, 2hrs frm mdnite!!
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