The all new Brain Teaser thread..with knobs on!

And to get the ball rolling...

The Tate Modern decided to introduce a new conceptual art piece. The artist was instructed to create a huge pile of different paintings; periodically pick up one of the paintings and hang it on the wall, then adjust it.

At 11:00, the painting titled "Number 30" was hung.

At 4:00, the painting titled "Number 240" was hung.

At 7:30, the painting titled "Number 315" was hung.

What painting will the artist hang on the wall at 9:20?

Answer: The answer is number 200. It is the angle between the hour hand and the minute hand at those respective times.

What are the largest and smallest 5-digit numbers that satisfy the following conditions?

• Each digit of the number is a prime number.
• Each successive pair of digits forms a 2-digit number that is NOT a prime number.
• Each of the prime digits must appear at least once in the 5-digit number.

Answer:
Largest - 35772
Smallest - 32257

First one:

Answer: 200 (ish?) Can't be bothered to work it out exactly, but I understand the logic. It's pretty close to that.

Second one:

Meh. Started looking at it and got bored.

Edit: Oh...there are answers. lol
Bollocks. Forgot they don't class "1" as prime. That's why I was struggling with rearranging 12357 to make non-prime pairs :)

According to the American Constitution, in order to became President of the United States there are only five pre-requisites. The candidate must:

1. be at least 35 years old.
2. be a citizen of the United States.
3. have resided in the United States for at least 14 years.
4. have been born in the United States.

What is the fifth requirement?

ANS: They must also be elected!
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How many legs does an elephant have if you call its trunk a leg?

ANS: 4, calling the trunk a leg doesn't make it so.
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In a dictionary, the verb 'BE' is described as:

BE [verb]

first and third person singular past indicative: was
second person singular and plural and first and third person plural past indicative: were
past subjunctive: were
past participle: been
present participle: being
first person singular present indicative: am
second person singular and plural and first and third person plural present indicative: are
third person singular present indicative: is
present subjunctive: be

Therefore you can correctly say 'I am', 'she is', 'you are', etc. Is it ever grammatically correct to say 'I is'?

ANS: Yes, using I as a letter rather than a word
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How should GHOTI be pronounced?

ANS: Fish (GH as in trouGH, O as in wOmen, TI as in moTIon)
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Question 7 on the local pub quiz was:

Name an ancient invention, which is still used in some parts of the world today, that allows people to see through walls.

What can this be?

ANS: A window
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Can you find something which has keys that open no locks, with space but no room, and allows you to enter but not to go in?

ANS: A keyboard
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What do you need for brushing your teeth, combing your hair and keeping the rain off?

ANS: A toothbrush, a comb and an umbrella

Quote:

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Originally Posted by JK Ferret

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How should GHOTI be pronounced?
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Fish :D

Quote:

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Question 7 on the local pub quiz was:
Name an ancient invention, which is still used in some parts of the world today, that allows people to see through walls.
What can this be?

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Glass..?

Quote:

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Therefore you can correctly say 'I am', 'she is', 'you are', etc. Is it ever grammatically correct to say 'I is'?

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To turn fish into fash, the i is replaced with a.

Quote:

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Originally Posted by JK Ferret

Question 7 on the local pub quiz was:

Name an ancient invention, which is still used in some parts of the world today, that allows people to see through walls.

What can this be?
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Can you find something which has keys that open no locks, with space but no room, and allows you to enter but not to go in?
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What do you need for brushing your teeth, combing your hair and keeping the rain off?

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A window

A keyboard

Hands?

Quote:

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Originally Posted by sammyc

Fish :D



Glass..?

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Yes, and almost, see mycarsavw's answer :)

Quote:

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Originally Posted by Steve B

To turn fish into fash, the i is replaced with a.

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Correct in context, IF fash is a real word :D (no I don't think it is, and no I can't be arsed to find out)

Quote:

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Originally Posted by mycarsavw

A window

A keyboard

Hands?

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Yes, yes, and no :)



For the last one, try thinking a little outside the mental box ;)

Quote:

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Originally Posted by JK Ferret

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How many legs does an elephant have if you call its trunk a leg?
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Um.. four? As in, you can call its trunk a leg but it's not one :O_o1:?

Quote:

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What do you need for brushing your teeth, combing your hair and keeping the rain off?

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One hand, then...? Oh alright (goes to think outside the mental box :rolleyes:)

Yes :) and further from the box, you're over-complicating it :)

Say what you see:

H I J K L M N O

Quote:

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Originally Posted by JK Ferret

According to the American Constitution, in order to became President of the United States there are only five pre-requisites. The candidate must:

1. be at least 35 years old.
2. be a citizen of the United States.
3. have resided in the United States for at least 14 years.
4. have been born in the United States.

What is the fifth requirement?

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They must be elected. <-- Are you sure this isn't the joke thread.:rolleyes:

Quote:

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Originally Posted by JK Ferret

Say what you see:

H I J K L M N O

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Water :P

Quote:

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Originally Posted by JK Ferret

Yes, yes, and no :)



For the last one, try thinking a little outside the mental box ;)

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Teeth, hair and an umbrella?

Quote:

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Originally Posted by Lanky123

They must be elected. <-- Are you sure this isn't the joke thread.:rolleyes:

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Yes... and fairly ;)

Quote:

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Originally Posted by Nick

Water :P

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Quite so

Quote:

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Originally Posted by mycarsavw

Teeth, hair and an umbrella?

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No, no, yes. On the right track, how does an umbrella differ?

Dag nabbit!

A toothbrush, a comb and an umbrella?

Quote:

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Originally Posted by mycarsavw

Dag nabbit!

A toothbrush, a comb and an umbrella?

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Much better, and far more correct :)







A man is walking downstairs in a building, when all the lights go out. He suddenly knows that his wife has died. How?

Quote:

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Originally Posted by JK Ferret

A man is walking downstairs in a building, when all the lights go out. He suddenly knows that his wife has died. How?

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He's wired her up to the Teasmade...? :mrgreen:

Quote:

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Originally Posted by JK Ferret

Much better, and far more correct :)


A man is walking downstairs in a building, when all the lights go out. He suddenly knows that his wife has died. How?

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Woo!

The building is a hospital and his wife is on life support?

Aye, damn power cuts eh?





A prisoner is in a room with no doors, no windows, nothing except a table. How does he get out?


HINT: You will need to sound out the words for this. And if you do manage to get it, you've a far better linguistics brain than I :)

He just walks out... just because there's no doors or windows doesn't means there aren't door frames or window frames . :)

He rubs his hands until they're SAW, uses the saw to cut the table in half, two halves make a HOLE, he jumps in the hole to escape.

Two men, 10 miles apart on a straight road walk towards each other, one at 3mph, and the other at 2mph. A dog running at 6mph leaves one man and runs until it meets the other. It then runs between the men at 6mph until all three meet. How far does the dog run?

The men cover 10 miles at a closing speed of 3+2+5 mph, taking 2 hours to meet. The dog runs for two hours at 6mph, and so covers 12 miles.

When does the dog leave the man?

A cylinder measuring 90 cm high has a circumference of 24 cm. A string makes exactly 5 complete turns round the cylinder while its two ends touch the cylinder's top and bottom. How long is the string in cm?

For the given problem, the cylinder can be unrolled into a rectangle with dimensions 90 cm by 24 cm. The string thus creates 5 diagonal lines whose measure can be found out by considering the 5 right triangles they can form: The base of the triangle is 24 cm and the height is 1/5 of 90 or 18 cm. From these workings, we can get the measurements of one diagonal line as 30 cm [i.e., (242 + 182) 1/2] by using the Pythagorean Theorem. Therefore, the whole string measures 150 cm

Quote:

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Originally Posted by clearlyolly

When does the dog leave the man?

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Doesn't matter :)

Jamie, Duncan and Ross are talking about their ages. Duncan realises that his age plus Ross's age is a perfect square. Ross notices that his age is an exact multiple of the sum of Jamie's and Duncan's ages. Surprisingly Jamie's age multiplied by Ross's age is a perfect cube. What are their ages?

Jamie is 3, Duncan is 9 and Ross is 72

he breaks the table in half, 2 halves make a whole so he climbs out the hole :D

edit: bit late :p

Quote:

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Originally Posted by Dav0s

he breaks the table in half, 2 halves make a whole so he climbs out the hole :D

edit: bit late :p

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Technically, he isn't in a hole to begin with so he cant step out. He cant step into a hole either, as then the only way to get out would be to turn back the way he came. He must step through the hole. But what if he gets trapped in the void, being neither through the hole, nor not? where is he then?
eh? EH?!

Given the reciprocal function 1/x, rotated around the x-axis to produce a cone of infinite length, determine the amount of paint required to:

a. Paint the surface of the cone (assume the cone has effectively zero thickness, so inside/outside is irrelevant)
b. Fill the cone with paint.

Has this not now just got to maths? Integrate x^-1 through 360degrees.

Well yes technically it's just calculus, but it's a case of interest that some might recognise ;)

Quote:

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Originally Posted by Steve

Given the reciprocal function 1/x, rotated around the x-axis to produce a cone of infinite length, determine the amount of paint required to:

a. Paint the surface of the cone (assume the cone has effectively zero thickness, so inside/outside is irrelevant)
b. Fill the cone with paint.

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Enough pi to last you a very long time? ;-)

For the mathematically/programming inclined, I recommend the problems at http://projecteuler.net

how many bits of cheese does it take to fill a carrot-shaped mouse?

there are SO many variables there..

Quote:

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Originally Posted by 0iD

Two men, 10 miles apart on a straight road walk towards each other, one at 3mph, and the other at 2mph. A dog running at 6mph leaves one man and runs until it meets the other. It then runs between the men at 6mph until all three meet. How far does the dog run?

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Quote:

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Originally Posted by clearlyolly

When does the dog leave the man?

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Quote:

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Originally Posted by 0iD

Doesn't matter :)

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Phew... managed to cut out the answer without seeing it :)

Of course it matters when, if the dog leaves the man at 10 miles apart, it'll run a lot farther than it would have at, say, 1 mile apart.

So, assuming the dog leaves at 10 miles apart, then

sM = 0m, vM = 2m/h, a = 0, t = ?
sD = 10m, vD = 6m/h, a = 0, t =?

using s=vt
we get (for D), 10 = 6t, giving t = 5/3

So at t=5/3, M is at S=2*5/3, = 10/3

Waitaminute... it's been too long since I's done maths, I'll have to paper this 'un, that looks completely incorrect

Brb ;)


EDIT: I give up, I has forgotten too much :(
EDIT2: well, having looked at the answer, I WAY overcomplicated it!

Quote:

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Originally Posted by Steve

Given the reciprocal function 1/x, rotated around the x-axis to produce a cone of infinite length, determine the amount of paint required to:

a. Paint the surface of the cone (assume the cone has effectively zero thickness, so inside/outside is irrelevant)
b. Fill the cone with paint.

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good old gabriel's horn :)
don't forget the domain, x> (or equal to) 1

a) infinite
b) pi(1-(1/a)) where a is the upper limit and is greater than 1

here for anyone that doesn't know what i'm on about

Secure Ltd recently showcased a series of three digit combination locks. The only problem is they were slightly defective. No combinations that started or ended in a zero would work, and combinations worked whether they were entered backwards or forwards. Assuming the no 0x0 combo should be tried, how many combinations would a cracker have to try before they were guaranteed to find one that works?


# combos not in form xyx / 2 + # combos in form xyx

= (9*10*9 - 9*10*1) / 2 + 9*10*1 = 450

A factory that produces tables and chairs is equipped with 10 saws, 6 lathes, and 18 sanding machines. It takes a chair 10 minutes on a saw, 5 minutes on a lathe, and 5 minutes of sanding to be completed. It takes a table 5 minutes on a saw, 5 minutes on a lathe, and 20 minutes of sanding to be completed. A chair sells for &#163;10 and a table sells for &#163;20. How many tables and chairs should the factory produce per hour to yield the highest revenue, and what is that revenue?


Solution:

The optimal answer is to make 24 chairs and 48 tables for revenue of $1200 per hour.
To check it will take 24*10 + 48*5 = 480 minutes of saw time. There are 600 minutes available so the saws will be idle 20&#37; of the time.
It will take 24*5 + 48*5 = 360 minutes of lathe time which is exactly what we have.
It will take 24*5 + 48*20 = 1080 minutes of sanding machine time which is exactly what we have.

This weeks is:
A right cylinder, with a diameter congruent to its height is inscribed in a right cone with height 12 units and radius 5 units. If their axes coincide, find the radius of the cylinder. Hint: By inscribed, this means that the cylinder's whole bottom face is touching the cone's bottom face, and the cylinder is touching the cone with the circumference of the top face.


Solution:

Imagine the axis of the cone form a right triangle. This triangle shares the dimensions of the cone, so it is 12 by 5. Imagine a radius that intersects the hypotenuse of the triangle and call it x. Therefore, we get a right triangle with a smaller right triangle inside. Thus, we can set up a proportion: 12/5 = 12-2x/x. After cross multiplying we get 30/11

Which football team always plays in 2-5-3 (2 defenders, 5 midfielders and 3 forwards) formation?



A table football team

Duncan and Jamie were going to cut the grass on their square lawn. They agreed that each should cut one-half of the area. Duncan went first, and cut a border 2 metres wide all the way around. After doing a few sums, Jamie agreed that exactly one-half had been cut and happily cut the rest. What was the area of the lawn?


Solution:

Area of lawn was 186.51 square metres.