GAME: Brain Teasers

Post by **Woodles** » Sun Dec 14, 2014 1:13 pm

Good idea Chris

Joshrandom wrote:Q6. I drive my old Ford Focus around a mile long race circuit and finish the lap with an average speed of 30mph, I decide to do another lap of the same circuit, but how fast do I need to go on this second lap if I want to complete both laps at an average speed of 60mph? :scratch:

A6. Lightspeed!

A 1 mile track done once at 30mph average speed takes 2 minutes.
A 1 mile track done twice at 60mph average speed takes 2 minutes.

No more time left after the first run

Post by **Woodles** » Sun Dec 14, 2014 1:16 pm

rich2000k wrote:Q8 A horse is on a 24 foot chain and wants an apple that is 26 feet away. How can the horse get to the apple?

A8. The chain is anchored between the horse and the apple

Or ... the other end of the chain isn't fastened to anything

Post by **Woodles** » Sun Dec 14, 2014 1:24 pm

For the mathematicians among us:

Q9. Find the mistake:

A = B
A*B = B*B
A*A - A*B = A*A - B*B
A(A-B) = (A+B)*(A-B)
A = A+B
BUT, A=B therefore A = 2A and 1=2!

Post by **rich2000k** » Sun Dec 14, 2014 2:12 pm

Well done Woodles correct, the chain wasn't tied to anything.

Post by **UBT - Chris** » Sun Dec 14, 2014 2:56 pm

A7: Nothing

Post by **Woodles** » Sun Dec 14, 2014 3:33 pm

Well done Chris, that one had me stumped.

Post by **UBT - Mikee** » Sun Dec 14, 2014 3:37 pm

Q 10

Easy one for you...

A bat and ball cost one pound and ten pence. The bat costs one pound more than the ball.

How much does the ball cost?

Mike

Post by **Joshrandom** » Mon Dec 15, 2014 2:01 am

Woodles wrote:A6. Lightspeed!

A 1 mile track done once at 30mph average speed takes 2 minutes.
A 1 mile track done twice at 60mph average speed takes 2 minutes.

No more time left after the first run

Well done Mark, and well done to Mike who I think had worked it out too.

Most people answer 90mph, but as Mark showed, you have to think in terms of the time taken for each lap.

Post by **Joshrandom** » Mon Dec 15, 2014 2:09 am

Woodles wrote:For the mathematicians among us:

Q9. Find the mistake:

A = B
A*B = B*B
A*A - A*B = A*A - B*B
A(A-B) = (A+B)*(A-B)
A = A+B
BUT, A=B therefore A = 2A and 1=2!

Since A = B , (A-B) = 0 therefore the line A(A-B) = (A+B)*(A-B) is actually A*0 = (A+B)*0 and anything multiplied by zero is zero, so eliminating the zero from both sides of the equation has no mathematical meaning.

Post by **Woodles** » Mon Dec 15, 2014 9:00 am

Joshrandom wrote:
Woodles wrote:For the mathematicians among us:

Q9. Find the mistake:

A = B
A*B = B*B
A*A - A*B = A*A - B*B
A(A-B) = (A+B)*(A-B)
A = A+B
BUT, A=B therefore A = 2A and 1=2!
Since A = B , (A-B) = 0 therefore the line A(A-B) = (A+B)*(A-B) is actually A*0 = (A+B)*0 and anything multiplied by zero is zero, so eliminating the zero from both sides of the equation has no mathematical meaning.

Very good James, looks like I'm not the only one who likes playing with numbers

Post by **Woodles** » Mon Dec 15, 2014 9:01 am

UBT - Mikee wrote:Q 10

Easy one for you...

A bat and ball cost one pound and ten pence. The bat costs one pound more than the ball.

How much does the ball cost?

Mike

A10 I'm going for 5p

Mark

Post by **Woodles** » Mon Dec 15, 2014 9:06 am

A classic:

Q11 A farmer has a bag of corn, a hen and a sheepdog to transport across the river.

His boat can only carry him and one other item at a time.

The sheepdog will eat the hen if left alone with it, the hen will eat the corn if left alone with it, the corn is vegetarian and won't eat either of the others

How does he get them all across the river successfully?

(To save the smart alec answers, the river is too wide to throw things across, neither the dog nor hen can swim and the bag of corn sinks

)

Post by **UBT - Mikee** » Mon Dec 15, 2014 9:45 am

Woodles wrote:
UBT - Mikee wrote:Q 10

Easy one for you...

A bat and ball cost one pound and ten pence. The bat costs one pound more than the ball.

How much does the ball cost?

Mike
A10 I'm going for 5p

Mark

Well done - most people assume it's 10p. I posted the speed answer on white text so no one would see it.

Mike

Post by **Woodles** » Mon Dec 15, 2014 11:58 am

UBT - Mikee wrote: Well done - most people assume it's 10p. I posted the speed answer on white text so no one would see it.

Mike

So you had, I thought you were just being wasteful with the formatting

Mark

Post by **UBT - Timbo** » Mon Dec 15, 2014 12:34 pm

UBT - Mikee wrote:Tim - can we move this thread to the Team Cafe section?

I think we need to have a couple of rules for this.

1 - Quote original question in the answer - otherwise it's gonna get confusing when other members post questions before others are answered.

2 - Don't post your answers too quickly - we need to give other people a chance to answer and make their brain hurt! So something like allow 6 hours before answers are given even if they're wrong!

or

if you have to give an answer you could post your reply as white text on a white background?

Mike

Hi Mike

I've moved the thread as requested

regards
Tim

Post by **UBT - Chris** » Mon Dec 15, 2014 5:02 pm

Q12: If you drove a bus with 43 people on board from London and stopped at Liverpool to pick up 7 more people, what's the name of the driver?

Post by **UBT - Chris** » Mon Dec 15, 2014 5:02 pm

Q13: Do they have a 4th July in England?

Post by **UBT - Chris** » Mon Dec 15, 2014 5:03 pm

Q14: How many birthdays does the average man have?

Post by **UBT - Chris** » Mon Dec 15, 2014 5:05 pm

Q15: Is it legal for a man in California to marry his widow's sister?

Post by **UBT - Mikee** » Mon Dec 15, 2014 6:15 pm

Woodles wrote:A classic:

Q11 A farmer has a bag of corn, a hen and a sheepdog to transport across the river.

His boat can only carry him and one other item at a time.

The sheepdog will eat the hen if left alone with it, the hen will eat the corn if left alone with it, the corn is vegetarian and won't eat either of the others

How does he get them all across the river successfully?

(To save the smart alec answers, the river is too wide to throw things across, neither the dog nor hen can swim and the bag of corn sinks )

Like these old ones!

Let's see if I remember!

Take the chicken acoss and come back.
Take the corn across and come back with the chicken.
Take dog across then come back for the chicken.

That right?

Mike