# Math Is Fun Forum

Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫  π  -¹ ² ³ °

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## #1 2008-07-25 09:58:39

careless25
Real Member
Registered: 2008-07-24
Posts: 560

### Brain Teasers

1)
There are 70 clerks working with Messrs STEVE STEEVE StEAVE & Co, Chartered accountants, of which 30 are females. Also-
a)30 clerks are married;
b)24 clerks are above 25 years of age;
c)19 married clerks are above 25 years, of whch 7 are males;
d) 12 males are above 25 years of age; and
e) 15 males are married
How many bachelor girls are there and how many of these are above 25?
2) Can you write:
a) 1 by using all ten digits (each digit used once only)?
b) 100 with five identical digits?
c) 1000 with eight-
(i)8's?
(ii)4's?
(iii)5's?
(iv)7's?
(v) of any digit other than zero?

Last edited by careless25 (2008-07-25 10:28:08)

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## #2 2008-07-25 10:34:24

careless25
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Registered: 2008-07-24
Posts: 560

### Re: Brain Teasers

kylekatarn wrote:

2.a)
( (9 - 8) + (7 - 6) ) - ( ( 5 - 4 ) + ( 3 - 2 ) ) + 1 + 0 = 1

?

pls hide if u are postin answers.
Yes that is correct and for 2a there are 3 more possibilities!!

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## #3 2008-07-25 10:48:02

careless25
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Registered: 2008-07-24
Posts: 560

### Re: Brain Teasers

3)This was carved on Diophantuss' tomb:
"God granted him to be a boy for the sixth part of his life, and adding a twelfth part to this, He clothed his cheeks with down; He lit him the light of wedlock after a seventh part, and five years after his marriage He granted him a son.Alas! late-born wretched child; after attaining the measure of half his father's full life, chill Fate took him. After consoling his grief by this science of numbers for four years he ended his life."
How old was Diophantus when he died?

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## #4 2008-07-25 11:12:40

mathsyperson
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Registered: 2005-06-22
Posts: 4,900

### Re: Brain Teasers

Also, there are millions (probably) of possibilities for 2a.

Why did the vector cross the road?
It wanted to be normal.

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## #5 2008-07-25 11:18:48

careless25
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Registered: 2008-07-24
Posts: 560

### Re: Brain Teasers

Mathys you got number 1 right. Great Job!

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## #6 2008-07-25 11:21:15

careless25
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Registered: 2008-07-24
Posts: 560

### Re: Brain Teasers

for 2 you can use tens unit and thousands units. Dont get stuck on the ones.

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## #7 2008-07-25 11:52:52

careless25
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Registered: 2008-07-24
Posts: 560

### Re: Brain Teasers

4)
Late one night BOOKWORM was studying for his examinations when the lights went out. He lighted two candles of equal length, one thicker than the other. The thich candle is supposed to last six hours and the thin one two hours less. When BOOKWORM finally went to sleep the thick candle was twice as long as the thin one.
For how long did BOOKWORM study?

5)LAZY, SLOW and IDLE are working with Messrs Drousy Daughters at Dull-Louise. On every working day they lunch together at SLICK SLUMS where they also order beer based on the following premises:
a)Idle has beer only if either Lazy or Slow or both have it.
b) Unless neither Lazy nor Slow have beer, Idle must have it.
c) Slow and Idle never have been together
d) if lazy does not have beer, either Slow or Idle or both have it.
Who orders beer?

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## #8 2008-07-25 20:03:15

ZHero
Real Member
Registered: 2008-06-08
Posts: 1,889

### Re: Brain Teasers

If two or more thoughts intersect, there has to be a point!

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## #9 2008-07-25 21:46:09

JaneFairfax
Member
Registered: 2007-02-23
Posts: 6,868

### Re: Brain Teasers

Last edited by JaneFairfax (2008-07-25 22:10:57)

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## #10 2008-07-25 21:58:56

JaneFairfax
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Registered: 2007-02-23
Posts: 6,868

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## #11 2008-07-26 01:52:02

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

### Re: Brain Teasers

Why did the vector cross the road?
It wanted to be normal.

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## #12 2008-07-26 02:06:27

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,588

### Re: Brain Teasers

What is "5c" trying to say?  I thought all 3 go to the drinking place each day.

igloo myrtilles fourmis

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## #13 2008-07-26 02:48:24

JaneFairfax
Member
Registered: 2007-02-23
Posts: 6,868

### Re: Brain Teasers

mathsyperson wrote:

Last edited by JaneFairfax (2008-07-26 03:13:41)

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## #14 2008-07-26 02:51:43

ZHero
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Registered: 2008-06-08
Posts: 1,889

### Re: Brain Teasers

mathsyperson wrote:

I hope you're joking!

If two or more thoughts intersect, there has to be a point!

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## #15 2008-07-26 03:46:19

careless25
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Registered: 2008-07-24
Posts: 560

ZHero wrote:

yes u r right!!

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## #16 2008-07-26 03:47:23

careless25
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Registered: 2008-07-24
Posts: 560

### Re: Brain Teasers

JaneFairfax wrote:

Number 5 is wrong but u have everything else right!

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## #17 2008-07-26 03:48:49

careless25
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Registered: 2008-07-24
Posts: 560

### Re: Brain Teasers

mathsyperson wrote:

i dont agree with 4 but 5 is right!

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## #18 2008-07-26 03:50:32

careless25
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Registered: 2008-07-24
Posts: 560

### Re: Brain Teasers

2a)

Last edited by careless25 (2008-07-26 03:52:53)

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## #19 2008-07-26 04:48:06

careless25
Real Member
Registered: 2008-07-24
Posts: 560

### Re: Brain Teasers

any1 tryin number 3? or shouldi post answer n explanation?

6)On an island there live three tribes; the Truthers always answer truthfully, the Liars always answer falsely and the Alternators alternate true and false answers. On your first visit to the island, you come across a tribesman. How will you, in just one question, determine the tribe he belongs to?

7) On a certain pasture the grass grows at an even rate. it is known that 40 cows can graze on it for 40 days before thr grass is exhausted, but 30 cows can graze there as long as 60 days.
How many days would the pasture lastif 20 cows were to graze on it?

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## #20 2008-07-26 06:06:02

ZHero
Real Member
Registered: 2008-06-08
Posts: 1,889

### Re: Brain Teasers

If two or more thoughts intersect, there has to be a point!

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## #21 2008-07-26 06:31:08

mathsyperson
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Registered: 2005-06-22
Posts: 4,900

### Re: Brain Teasers

JaneFairfax wrote:

#4: ZHero is right.
...

Ah, true enough. I read "two hours less" in the question as just "two hours". The bracketed part of my answer is still right though.

Edit: Ah, Jane got there first. At least we agree this time.

Last edited by mathsyperson (2008-07-26 06:42:35)

Why did the vector cross the road?
It wanted to be normal.

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## #22 2008-07-26 06:35:07

JaneFairfax
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Registered: 2007-02-23
Posts: 6,868

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## #23 2008-07-26 06:36:59

ZHero
Real Member
Registered: 2008-06-08
Posts: 1,889

### Re: Brain Teasers

mathsyperson wrote:

The bracketed part of my answer is still right though.

:):D:D:):)

If two or more thoughts intersect, there has to be a point!

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## #24 2008-07-26 06:50:12

ZHero
Real Member
Registered: 2008-06-08
Posts: 1,889

### Re: Brain Teasers

Hey Jane! We ended up answering the question almost at the same instant!?
However,

was different!

Last edited by ZHero (2008-07-26 06:54:28)

If two or more thoughts intersect, there has to be a point!

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## #25 2008-07-26 07:08:15

JaneFairfax
Member
Registered: 2007-02-23
Posts: 6,868

### Re: Brain Teasers

Yes, that works too. Well done to both of us.

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