GAME: Brain Teasers

Here's the place to post all sorts of games, quizzes, or interactive competitions etc for forum members to join in with....
Joshrandom
UBT Contributor
Posts: 5602
Joined: Sat Jun 23, 2007 1:00 am

Post by Joshrandom » Tue Dec 16, 2014 7:04 pm

Woodles wrote:Q21. Draw a grid of 4*4 squares.
How many squares of all sizes are there in total?
Working it out in my head gives me 30 squares, but I've probably missed something obvious. :?

Joshrandom
UBT Contributor
Posts: 5602
Joined: Sat Jun 23, 2007 1:00 am

Post by Joshrandom » Tue Dec 16, 2014 7:08 pm

UBT - Mikee wrote:I posted the speed answer on white text so no one would see it.

Mike
So you did, missed that, and you were even more accurate than Mark was in his answer.  :wink:

Woodles
Active UBT Contributor 15+ yrs
Posts: 9279
Joined: Thu Dec 20, 2007 12:00 am
Location: Cambridgeshire

Post by Woodles » Tue Dec 16, 2014 7:36 pm

Correct James, you didn't miss anything.

And well done with the river question, didn't think of that.
Image

Joshrandom
UBT Contributor
Posts: 5602
Joined: Sat Jun 23, 2007 1:00 am

Post by Joshrandom » Tue Dec 16, 2014 7:45 pm

Another oldie.

Q23. Explain where the extra square comes from in figure B when you rearrange the shapes in figure A.

Image

Woodles
Active UBT Contributor 15+ yrs
Posts: 9279
Joined: Thu Dec 20, 2007 12:00 am
Location: Cambridgeshire

Post by Woodles » Tue Dec 16, 2014 10:16 pm

Joshrandom wrote:Another oldie.

Q23. Explain where the extra square comes from in figure B when you rearrange the shapes in figure A.

Image
A23. Magic? The hypotenuse isn't a straight line
Image

UBT - Mikee
Marvin the Dalek
Posts: 4048
Joined: Wed Mar 15, 2006 12:00 am
Location: North Wales

Post by UBT - Mikee » Tue Dec 16, 2014 10:30 pm

Joshrandom wrote:Another oldie.

Q23. Explain where the extra square comes from in figure B when you rearrange the shapes in figure A.

Image
There's a barely perceptible 'bend' in the slope of triangle A which 'straightens' out on triangle B. The difference is exactly 1 square.
Follow us on Twitter... http://twitter.com/UKBOINCTeam

Image Image

Image

UBT - Mikee
Marvin the Dalek
Posts: 4048
Joined: Wed Mar 15, 2006 12:00 am
Location: North Wales

Post by UBT - Mikee » Tue Dec 16, 2014 10:39 pm

Woodles wrote:Q22. A couple have a dog, a cat and a parrot as pets, how many toes are there in the household?
Not sure how many toes a parrot has - 8? Just counted one of my cats toes and it appears to have 4 per foot (16), a dog the same (16)? 8 for the parrot and 20 for the couple = 60? Seems a lot! :-)
Follow us on Twitter... http://twitter.com/UKBOINCTeam

Image Image

Image

Woodles
Active UBT Contributor 15+ yrs
Posts: 9279
Joined: Thu Dec 20, 2007 12:00 am
Location: Cambridgeshire

Post by Woodles » Tue Dec 16, 2014 10:47 pm

UBT - Mikee wrote:
Woodles wrote:Q22. A couple have a dog, a cat and a parrot as pets, how many toes are there in the household?
Not sure how many toes a parrot has - 8? Just counted one of my cats toes and it appears to have 4 per foot (16), a dog the same (16)? 8 for the parrot and 20 for the couple = 60? Seems a lot! :-)
Close Mikee, count your cats toes again. Hint, they're not all in the same place :D
Image

UBT - Timbo
UBT Forum Admin
Posts: 7095
Joined: Mon Mar 13, 2006 12:00 am
Location: NW Midlands
Contact:

Post by UBT - Timbo » Wed Dec 17, 2014 12:14 am

A20 - a bit late....but the dog was called Muttley and he flew over the river.... :)

hgblade
UBT Contributor
Posts: 28463
Joined: Fri Jan 04, 2008 12:00 am

Post by hgblade » Wed Dec 17, 2014 12:20 am

Woodles wrote:
hgblade wrote:Here's one for you:

Q20. A man stands on one side of a wide river. He calls his dog, who is on the opposite side of the river and the dog comes over to him. When the dog arrives he hasn't got wet and didn't use a bridge or boat, nor was he carried over. How did the dog manage to stay dry?
How good's the dog at walking on stilts? :D
Nice try!!!! (but wrong)  :lol:  :lol:
Image

hgblade
UBT Contributor
Posts: 28463
Joined: Fri Jan 04, 2008 12:00 am

Post by hgblade » Wed Dec 17, 2014 12:21 am

Joshrandom wrote:
hgblade wrote:Here's one for you:

Q20. A man stands on one side of a wide river. He calls his dog, who is on the opposite side of the river and the dog comes over to him. When the dog arrives he hasn't got wet and didn't use a bridge or boat, nor was he carried over. How did the dog manage to stay dry?
Well I'm guessing that either the dog is called 'who is on the opposite side of the river' :D , or the river is frozen over and the dog just walked across the ice.


...... and that won't do, either!!!  :lol:      (it really is quite a simple answer  :roll: )
Image

UBT - Timbo
UBT Forum Admin
Posts: 7095
Joined: Mon Mar 13, 2006 12:00 am
Location: NW Midlands
Contact:

Post by UBT - Timbo » Wed Dec 17, 2014 12:26 am

A23 - if you recall your trig from school, then you'll remember that the angle of a triangle can be calculated by opposite divided by adjacent....

In both triangles, the angle to the vertical in red section is 2/5 (=21.8014 degrees) and for the blue section it's 3/8 (=20.556 degrees). So for Triangle A, the long hypotenuse bows out at the left and then cuts inwards on the right, and for triangle B, the opposite occurs. So, it's an optical illusion that the hypotenuse's are both perfectly straight


Simples :)

UBT - Timbo
UBT Forum Admin
Posts: 7095
Joined: Mon Mar 13, 2006 12:00 am
Location: NW Midlands
Contact:

Post by UBT - Timbo » Wed Dec 17, 2014 12:29 am

Q24 What's more difficult than getting a pregnant elephant in the back of a mini ?

UBT - Chris
UBT Contributor
Posts: 602
Joined: Tue Nov 05, 2013 12:00 am

Post by UBT - Chris » Wed Dec 17, 2014 8:39 am

A20: was the river dry - i.e no water in it?
'UBT - Chris' is my old name - I now crunch as 'CaffeinatedSloth' but I'm still 100% UBT :D
Image
Image

UBT - Chris
UBT Contributor
Posts: 602
Joined: Tue Nov 05, 2013 12:00 am

Post by UBT - Chris » Wed Dec 17, 2014 8:39 am

A24: Being a pregnant elephant in the back of a mini ;)
'UBT - Chris' is my old name - I now crunch as 'CaffeinatedSloth' but I'm still 100% UBT :D
Image
Image

Woodles
Active UBT Contributor 15+ yrs
Posts: 9279
Joined: Thu Dec 20, 2007 12:00 am
Location: Cambridgeshire

Post by Woodles » Wed Dec 17, 2014 9:11 am

UBT - Timbo wrote:Q24 What's more difficult than getting a pregnant elephant in the back of a mini ?
A24. getting an elephant pregnant in the back of a mini!
Image

hgblade
UBT Contributor
Posts: 28463
Joined: Fri Jan 04, 2008 12:00 am

Post by hgblade » Wed Dec 17, 2014 10:27 am

UBT - Chris wrote:A20: was the river dry - i.e no water in it?
Nope - but a lot better than certain answers!!
Image

hgblade
UBT Contributor
Posts: 28463
Joined: Fri Jan 04, 2008 12:00 am

Post by hgblade » Wed Dec 17, 2014 12:41 pm

A little longer to mull over Q20, meanwhile .....

Q25. What is UNIQUE about the following number: 8,549,176,320?
Image

UBT - Timbo
UBT Forum Admin
Posts: 7095
Joined: Mon Mar 13, 2006 12:00 am
Location: NW Midlands
Contact:

Post by UBT - Timbo » Wed Dec 17, 2014 3:13 pm

A25 - every base 10 digit is used AND the numbers are in order as "spelt out"....Eight, Five, Four,

UBT - Timbo
UBT Forum Admin
Posts: 7095
Joined: Mon Mar 13, 2006 12:00 am
Location: NW Midlands
Contact:

Post by UBT - Timbo » Wed Dec 17, 2014 3:15 pm

Q26: A farmer challenges an engineer, a physicist, and a mathematician to fence off the largest amount of area using the least amount of fence.

The engineer made his fence in a circle and said it was the most efficient.

The physicist made a long line and said that the length was infinite. Then he said that fencing half of the Earth was the best.

The mathematician laughed at the others and with his design, beat the others. What did he do?

Post Reply