Puzzles

[firewalker99]

its a weird one!

the orange block = 7 squares
light green block = 8 squares
green triangle = 5 squares ( (5 x 2) / 2)
red triangle = 12 squares ( (8 x 3) / 2)

total surface area = 7 + 8 + 5 + 12 = 32 squares

big triangle = 32.5!!! ( (13 x 5) / 2)
I dont understand how the big triangle surface area is 0.5 square bigger than the smaller pieces added together.

Am I making false assumptions about the surface area of the triangles? (Length x Height / 2) ??

Your calculations are all correct

I mean, your approach to determine the surface (lxh /2) is correct. But the big triangle can't be different in surface area from the sum of the others obviously, so something else must be causing this ...

 

[bypath3]

with the triangles, one has a gradient of 5/2, 2.5, the other 8/3, 2.66.... and so the diagonal of the diagrams aren't 'smooth'.

 

[MrGecko]

it's not a f*cking triangle.

the two component triangles have different gradients; on the top triangle, the gradients are arranged in such a way that the true path of the QUADILATERAL swings out from the hypotenuse of the "fake" triangle; on the bottom, they are arranged so that the true path swings in; the area of the triangle created between the "fake" hypotenuse and the true path is equal to 0.5 squares - so the difference between the "swing out" quadilateral and the "swing in" quadilateral is 2 * 0.5 units = the extra square that magically appears.

i've even proven it (because I am a dork); the end result of 0.49999 units Squared is the discrepancy in area made by diverting from the apparent hypotenuse.

 

[new_trader]

it's not a f*cking triangle.

the two component triangles have different gradients; on the top triangle, the gradients are arranged in such a way that the true path of the QUADILATERAL swings out from the hypotenuse of the "fake" triangle; on the bottom, they are arranged so that the true path swings in; the area of the triangle created between the "fake" hypotenuse and the true path is equal to 0.5 squares - so the difference between the "swing out" quadilateral and the "swing in" quadilateral is 2 * 0.5 units = the extra square that magically appears.

i've even proven it (because I am a dork); the end result of 0.49999 units Squared is the discrepancy in area made by diverting from the apparent hypotenuse.

Oh derrr...

http://www.trade2win.com/boards/foyer/28356-puzzle-thread-answers-3.html#post428266

 

[firewalker99]

Thanks for the effort guys, some put a whole lot more effort in than necessarily

Unfortunately some people didn't realize we had a separate thread for the answers... perhaps I should've reminded people to post the answers not here.

Oh well, on to the next one...

 

[firewalker99]

Fun with movies

This isn't a puzzle as such, but I enjoyed it. Quite difficult though, even if you watched a lot of movies (like myself):

Fun Movie Quiz

There's also a second, third and fourth part:
Fun Movie Quiz - 2
Fun Movie Quiz - 3
Fun Movie Quiz - 4

I average about 10-15 points out of 30.

 

[MrGecko]

Unfortunately some people didn't realize we had a separate thread for the answers...

aahhhhh sh!t. Sorry guys, you've blown my cover; Cosine rule aside, I'm a dumbass

 

[firewalker99]

aahhhhh sh!t. Sorry guys, you've blown my cover; Cosine rule aside, I'm a dumbass

No worries As punishment you need to provide us with a puzzle yourself

 

[JTrader]

cognitive fun!

 

[firewalker99]

For old times sake...

You find yourself with nothing more than an old balance and 12 balls. One of them weighs more or less than the othe eleven, which are all equal in weight.

Know it's your task to determine which one that is, ànd tell me whether it's heavier or lighter. You can only use the balance to weigh 3 times, and you can't use anything or anyone to solve this. There's no magic, but I think you'll need pen & paper to solve this one.

Good luck!

 

[MrGecko]

Sorry Folks!!!!

I put my answer here, forgetting there is a seperate thread for the answers!!!!

http://www.trade2win.com/boards/foyer/28356-puzzle-thread-answers.html#post498726

Hope I didn't spoil it for anyone!!

 

[firewalker99]

Sorry Folks!!!!

I put my answer here, forgetting there is a seperate thread for the answers!!!!

http://www.trade2win.com/boards/foyer/28356-puzzle-thread-answers.html#post498726

Hope I didn't spoil it for anyone!!

No you didn't, it was a quick reply, but not a correct one. Alas!

 

[firewalker99]

cognitive fun!

You should try the dual n backtests...
Cognitive tests: Jaeggi-Buschkuehl dual n-back task

I'm going to have to work on that

 

[firewalker99]

Still nobody who figured out the balance puzzle?

 

[MrGecko]

This ones difficult... I've been working on a solution that splits the 12 balls up into 3 groups of 4, then re-distributing the balls around to try and pick out the odd one... don't tell us yet?

 

[rags2riches]

Still nobody who figured out the balance puzzle?

really tricky - gimme until EOD

 

[trendie]

Still nobody who figured out the balance puzzle?

its a toughie.
not only do you need to establish the odd-ball, but then additionally whether it is heavier/lighter than the others. to me, it uses up one extra weighing option.
maybe we could share our current thoughts, and then use it as basis for next step.

I thought along lines of MrGecko, in that if you weigh 4 against 4, if the balance tips, the remaining 4 are "baseline", then you could weigh one of the already weighed against it to tell whether they were heavier/lighter.

but I am sure if you had 6 against 6, then removed 3 from each, depending on whether the scales stayed the same (the 6 removed are identical) or rebalanced (meaning the 6 removed contain the offending ball) was one avenue I pondered before getting bored.

 

[firewalker99]

This ones difficult... I've been working on a solution that splits the 12 balls up into 3 groups of 4, then re-distributing the balls around to try and pick out the odd one... don't tell us yet?

really tricky - gimme until EOD

its a toughie.
not only do you need to establish the odd-ball, but then additionally whether it is heavier/lighter than the others. to me, it uses up one extra weighing option.
maybe we could share our current thoughts, and then use it as basis for next step.

I'm glad it's a challenging one! Must say, I spend quite a bit of time on that one myself, and at one point I thought it could not be done.

It's possible though, but you better write things down, make a schematic of sorts...
Here's a tip without giving anything away: try numbering the balls.

 

[MrGecko]

Ok, this is the line I'm taking:

split balls into three groups of 4

1a 1b 1c 1d... 2a 2b 2c 2d.... 3a 3b 3c 3d

weigh 1 vs 2

If they are EQUAL, then the odd ball must be in set 3, and all 1 and 2 are even...

ergo weigh 3a 3b 3c Vs 1a 1b 1c

if EVEN, odd ball is 3D, weigh against 1a to see if heavy or light

ELSE

if 3a 3b 3c > 1a 1b 1c => odd ball is HEAVY

therefore weigh 3a v. 3b...

if 3a > 3b then 3a is HEAVY
if 3a < 3b then 3b is HEAVY
if 3a = 3b then 3c is HEAVY

ditto if 3a 3b 3c < 1a 1b 1c

________________________________________

thats is if the 1st weighing session shows 1a 1b 1c 1d vs. 2a 2b 2c 2d to be EQUAL - if they are odd, it's a bit trickier, but I'll get there in the end.

Can we extend the deadline? what with all te sh!t going on today I wont be able to give it as much attention as it requires.... tomorrow perhaps?

 

[rags2riches]

its a toughie.
not only do you need to establish the odd-ball, but then additionally whether it is heavier/lighter than the others. to me, it uses up one extra weighing option.
maybe we could share our current thoughts, and then use it as basis for next step.

I thought along lines of MrGecko, in that if you weigh 4 against 4, if the balance tips, the remaining 4 are "baseline", then you could weigh one of the already weighed against it to tell whether they were heavier/lighter.

but I am sure if you had 6 against 6, then removed 3 from each, depending on whether the scales stayed the same (the 6 removed are identical) or rebalanced (meaning the 6 removed contain the offending ball) was one avenue I pondered before getting bored.

I am thinking about 5 vs 5 as the 1st step...