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Brain teasers

on Sun 11 Mar 2018 - 17:22
First topic message reminder :

1.Tom’s height is six feet, he’s an assistant at a butcher’s shop, and wears size 9 shoes. What does he weigh?
2.Feed me and I live, yet give me a drink and I die Who am I? .
3.What kind of room has no doors or windows?
4.What gets broken without being held?
5.What word describes a woman who does not have all her fingers on one hand?
6.What kind of tree can you carry in your hand?
7.Which word in the dictionary is spelled incorrectly?
8.A girl who was just learning to drive went down a one-way street in the wrong direction, but didn’t break the law. How is that possible? (Answer:
9.If you have me, you want to share me. If you share me, you haven’t got me. What am I?
10.He has married many women, but has never been married. Who is he?

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raymyjamie
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Re: Brain teasers

on Sun 14 Oct 2018 - 12:59
Derrrr, I was stymied at the start.

Couldn't understand the question LOL.

Well done myg
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Re: Brain teasers

on Sun 14 Oct 2018 - 17:01
This one took a bit of thinking as initially the average is somewhere between 1 and 10 .
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Re: Brain teasers

on Mon 15 Oct 2018 - 22:23
Hope you sleep tonight

Consider an arbitrary acute triangle ABC. Let E be the intersection of the bisector at vertex C and the bisection of the side AB. Let F and G be the projections of E on AC and BC respectively.

Since E belongs to the bisection of AB, we must have AE = BE. Also, since E belongs to the bisector of C, we must have EF = EG. However, this would imply that triangles AEF and BGF are identical, and then AF = BF. We also have that CF = CG, which implies that AC = BC. The arbitrarily chosen triangle ABC is isosceles!

Can you find where the logic fails?

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raymyjamie
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Re: Brain teasers

on Tue 16 Oct 2018 - 19:15
It was a little late for brain work last night when this was posted, and I’d had a few scoops LOL!!!!!

“Can you find where the logic fails?”

LOL Very Happy NO!!!!!

First of all the triangle ABC does not look like an isosceles triangle, which should have two equal sides.
The angles shown between lines CF and CG is clearly closer to 90 degrees than the angle between the lines at AF and AD which looks a more acute angle.
Those angles should be the same in an isosceles triangle.

Its not very obvious how point E has been achieved.

“However, this would imply that triangles AEF and BGF are identical, and then AF = BF”.
Triangle BGF does not exist.
The line BF does not exist.

I have not found where the logic is flawed, but I have pointed out some errors which are either typos or were wrong in the original text.
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Re: Brain teasers

on Tue 16 Oct 2018 - 21:27
I think the answer lies with inscribed and circumscribed circles. Inscribed centre is the point where angle bisectors meet and circumscribed centre is the point at which the perpendicular bisectors of the sides meet.Unless it is an equilateral triangle these will not be the same point
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Re: Brain teasers

on Tue 16 Oct 2018 - 21:41
Thanks for that myg.

I'm an ex draughtsman who knows a lot about geometry, (self praise is no recommendation LOL),

but I have to say that has me beaten.
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Re: Brain teasers

on Tue 16 Oct 2018 - 22:53
Point E as described is not where it is drawn. D should be nearer to B and E would be below the line AB on the on the circumference of the circumcircle.
Inscribed circle has the three sides as tangents and circumscribed circle has the three vertices on its circumference.
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Re: Brain teasers

on Tue 16 Oct 2018 - 23:05
Answer. I need a drink Very Happy

The bisector of C and the bisection of AB always intersect outside the triangle, on the circumcircle. One of the points F and G always lies on the segment AC or BC, and the other one does not.

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Re: Brain teasers

on Wed 17 Oct 2018 - 9:15
myg
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Re: Brain teasers

on Wed 17 Oct 2018 - 11:35
5+4=9
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Re: Brain teasers

on Wed 17 Oct 2018 - 12:07
yes myg, there are a few others.
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Re: Brain teasers

on Wed 17 Oct 2018 - 15:45
8-4=4 ,0+4=4
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mache
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Re: Brain teasers

on Wed 17 Oct 2018 - 15:51
b + 4 = 4 when b = 0

s + 4 = 4 when s = 0

E + 4 = 4 when E = 0
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Re: Brain teasers

on Thu 18 Oct 2018 - 14:26
Which one is the top view of the tower on the left? Explain

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maureen
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Re: Brain teasers

on Thu 18 Oct 2018 - 15:37
At a guess...B..only because of the colour sequence.
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raymyjamie
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Re: Brain teasers

on Thu 18 Oct 2018 - 19:15
As an ex draughtsman I would say ‘A’

Starting from the top.
The smaller diameter is top cylinder is orange .
The second purple cylinder you wouldn’t see.
The third orange cylinder you wouldn’t see.
The fourth slightly bigger purple cylinder would be seen thin shell.
The fifth slightly bigger orange cylinder would be a thin shell.
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Re: Brain teasers

on Thu 18 Oct 2018 - 19:31
I'm saying nothing to give others a chance
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raymyjamie
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Re: Brain teasers

on Thu 18 Oct 2018 - 19:42
@Admin wrote:I'm saying nothing to give others a chance

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Re: Brain teasers

on Thu 18 Oct 2018 - 19:57
@Admin wrote: Which one is the top view of the tower on the left?  Explain


Any more ?
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Gassey
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Re: Brain teasers

on Thu 18 Oct 2018 - 20:09
If the top Orange one is a hollow ring
at the third orange one is a spindle or
axle running all the way through its B
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Re: Brain teasers

on Thu 18 Oct 2018 - 21:45
Well don RMJ

If you look at to the tower from the above, the top layer is orange. So, the answer is definitely not C.

The second purple layer will not be seen from the above because it is the same size with the top layer.

And the third layer won't be seen either because it is smaller size than the top two layers.

The fourth layer will be the next one that's going to be seen from the above around the purple layer.

The last one is going to be the largest and and it is orange.

According to these, the answer is going to be A
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Re: Brain teasers

on Thu 18 Oct 2018 - 21:54
Yay!!!!!!!!!!!!!
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Re: Brain teasers

on Tue 6 Nov 2018 - 19:27
A fire engine travels seven miles to a fire at a speed of 36mph.

Its tank holds 500 gallons of water but it’s been leaking throughout the journey at a rate of 22.5 gallons per hour.

If the fire engine needs 497 gallons of water to put out the fire, will it succeed?
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raymyjamie
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Re: Brain teasers

on Tue 6 Nov 2018 - 20:03
To travel 7 miles the fire engine will take 7/36 x 60 = 11.667 minutes.

In that time it will lose 11.667/60 x 22.5 = 4.375 gallons

500 – 4.375 = 495.625 gallons

The answer is there wouldn’t be enough water.
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Re: Brain teasers

on Fri 9 Nov 2018 - 18:38
cheers

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Re: Brain teasers

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