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#101 2007-12-12 02:31:09

pi man
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Registered: 2006-07-06
Posts: 251

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#102 2007-12-12 16:59:03

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

Excellent, pi man! The solution you have posted is perfectly right!

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#103 2007-12-12 21:03:00

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

53. A man ate 100 bananas in five days, each day eating 6 more than the previous day. How many bananas did he eat on the first day?

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#104 2007-12-13 08:04:13

222kitti_kat
Member
Registered: 2007-12-06
Posts: 7

...Katie...

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#105 2007-12-13 17:14:14

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

Well done, 222kitti_kat!!!

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#106 2007-12-15 19:05:50

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

#54. It was calculated that 75 men could complete a piece of work in 20 days. When work was scheduled to commence, it was found necessary to send 25 men to another project. How much longer will it take to complete the work?

#55. A dishonest shopkeeper professes to sell pulses at the cost price, but he uses a false weight of 950gm. for a kg. His gain is %.

#56. A contractor agreeing to finish a work in 150 days, employed 75 men each working 8 hours daily. After 90 days, only 2/7 of the work was completed. Increasing the number of men by________ each working now for 10 hours daily, the work can be completed in time.

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#107 2007-12-15 22:50:36

JohnnyReinB
Member
Registered: 2007-10-08
Posts: 453

Re: Brain Teasers

"There is not a difference between an in-law and an outlaw, except maybe that an outlaw is wanted"

Nisi Quam Primum, Nequequam

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#108 2007-12-15 23:00:14

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

Well done, JohnnyReinB!!!

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#109 2007-12-18 01:40:34

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

#57. General Gasslefield, accused of high treason, is sentenced to death by the court-martial. He is allowed to make a final statement, after which he will be shot if the statement is false or will be hung if the statement is true. Gasslefield makes his final statement and is released. What could he have said?

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#110 2007-12-18 02:01:50

TheDude
Member
Registered: 2007-10-23
Posts: 361

Wrap it in bacon

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#111 2007-12-18 02:27:25

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

All correct, well done!!!

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#112 2008-01-02 20:03:45

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

#58. A wizard named Nepo says "I am only three times my son's age. My father is 40 years more than twice my age. Together the three of us are a mere 1240 years old." How old is Nepo?

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#113 2008-01-02 21:45:06

JohnnyReinB
Member
Registered: 2007-10-08
Posts: 453

Re: Brain Teasers

"There is not a difference between an in-law and an outlaw, except maybe that an outlaw is wanted"

Nisi Quam Primum, Nequequam

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#114 2008-01-02 22:52:51

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

Correct, JohnnyReinB!
Keep it up!

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#115 2008-05-15 20:53:52

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

#59. Fill in the blank:-

15, 34, ____, 111, ...............

#60. In India, currency is available in denomination of Re 1, Rs 2, Rs 5, Rs 10, Rs 20. Rs 50,
Rs 100, Rs 500, and Rs 1000. If I have Rs 1000 in all, how many minimum notes must I possess in order to be able to give away any sum from Re 1 to Rs 1000 (counting numbers)?

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#116 2008-05-15 21:26:39

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

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#117 2008-05-15 21:31:01

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

Solution to #59:-
JaneFairfax, please check whether all the terms conform to the formula you have given.

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#118 2008-05-15 21:38:13

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

Re: Brain Teasers

Yes, its correct.

The solution to #59 it not unique. Just because you have your own answer doesnt there are no other correct ones. If you want to us to give your own answer, you need to give more clues to narrow down the possibilities (e.g. is the formula polynomial, exponential, or whatever).

Last edited by JaneFairfax (2008-05-16 06:35:13)

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#119 2008-05-15 22:11:19

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

JaneFairfax,
I performed a quick mental calculation for all the terms applying Lagrange's Interpolation formula and I got one of the terms in the series wrong, by oversight.
I apologize my post was hurriedly done.

The question relates to recreational mathematics. After someone posts the solution I have in my mind, or I do, you'd notice that this solution too perfectly fits in the series.

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#120 2008-05-15 22:13:21

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

Re: Brain Teasers

Just to prove that there are infinitely many answers for #59,

where K is any real number (or even complex number) you like!

Last edited by JaneFairfax (2008-05-15 22:15:48)

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#121 2008-05-15 22:42:17

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

#61. A lottery ticket series has the first two slots alphabetical in character and the next three slots numerical in character. The alphabetcial slots can take any value from A to Z and the numerical slots can take any value from 0 to 9. How many minimum tickets must I buy in order to make my success rate greater than 2.5%?

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#122 2008-05-20 23:52:10

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

#62. A rich merchant had collected many gold coins. He did not want anybody to know about them. One day, his wife asked, "How many gold coins do we have?"

After pausing a moment, he replied, "Well! If I divide the coins into two unequal numbers, then 50 times the difference between the two numbers equals the difference between the squares of the two numbers."

The wife looked puzzled. Can you help the merchant's wife by finding out how many gold coins they have?

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#123 2008-05-21 01:05:44

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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#124 2008-05-21 10:50:39

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

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#125 2008-05-21 17:55:33

ganesh
Registered: 2005-06-28
Posts: 23,085

Re: Brain Teasers

Solutions to #61 and #62:
Well done, mathsyperson and JaneFairfax!
Both of you are correct!

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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