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#3851 2015-07-22 01:16:43

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;



In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#3852 2015-07-22 03:33:23

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Oral puzzles

Hi bobbym,

All the parts of the solution #2412 are correct! Excellent!

#2413. In an Arithmetic Progression of 50 terms, the sum of first 10 terms is 210 and the sum of its last terms is 2565. Find the first 4 terms.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

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#3853 2015-07-22 15:51:21

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#3854 2015-07-22 16:12:43

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Oral puzzles

Hi bobbym,

Corrigendum :

#2413. In an Arithmetic Progression of 50 terms, the sum of first 10 terms is 210 and the sum of its last 15 terms is 2565. Find the first 4 terms.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

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#3855 2015-07-23 04:55:19

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#3856 2015-07-23 14:05:19

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Oral puzzles

Hi bobbym,

The solution #2413 is perfect! Neat work!

#2414. From a solid cylinder of height 2.8 centimeters and diameter 4.2 centimeters, a conical cavity of the same height and same diameter is hollowed out. Find the total surface area of the remaining solid.

.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

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#3857 2015-07-24 03:29:07

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#3858 2015-07-24 14:08:35

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Oral puzzles

Hi bobbym,

#2415. If A (-3,5), B (-2,-7), C (1,-8), and D (6,3) are the vertices of a quadrilateral ABCD, find its area.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

Offline

#3859 2015-07-24 14:17:06

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#3860 2015-07-24 15:19:51

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Oral puzzles

Hi bobbym,

#2416. The sum of the first seven terms of an Arithmetic Progression is 182. If its 4th and 17th terms are in the ratio 1:5, find the first four terms.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

Offline

#3861 2015-07-27 07:41:03

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#3862 2015-07-27 15:20:59

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Oral puzzles

Hi bobbym,

#2417.  Solve :

.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

Offline

#3863 2015-07-27 17:11:43

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#3864 2015-07-27 18:42:35

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Oral puzzles

Hi bobbym,

The two solutions of #2417 are correct! Remarkable!

#2418. Find the point P on the y-axis which is equidistant from the points A (4,8) and B (-6,6). Also, find the distance AP.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

Offline

#3865 2015-07-27 19:09:07

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#3866 2015-07-27 21:37:33

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Oral puzzles

Hi bobbym,

Homage to Dr.A.P.J.Abdul Kalam : (15 October 1931 – 27 July 2015) He was the 11th President of India from 2002 to 2007.

May His Soul Rest In Peace.

The solution #2418 is perfect! Neat work!

#2419. Five cards - the ten, jack, queen, king, and ace of diamonds, are well shuffled with their faces downwards. One card is then picked at random.
(a) What is the probability that the drawn card is the queen?
(ib) If the queen is drawn and set aside and a second card is drawn, find the probability that the second card is (i) an ace (ii) a queen.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

Offline

#3867 2015-07-28 05:08:43

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#3868 2015-07-28 15:15:05

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Oral puzzles

hi bobbym,

The solution #2419 (all parts) are correct! Neat work!

#2420. A motor boat whose speed in still water is 18 kilometers per hour, takes 1 hour more to go 24 kilometers upstream than to return downstream to the same spot. Find the speed of the stream. (in kilometers per hour).


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

Offline

#3869 2015-07-28 19:36:37

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#3870 2015-07-28 20:51:42

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Oral puzzles

Hi bobbym,

The solution #2420 is correct! Good work!

#2421. Find the ratio in which the line segment joining the points A (3,-3) and B (-2,7) is divided by x-axis. Also find the coordinates of the point of division.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

Offline

#3871 2015-07-29 19:06:59

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#3872 2015-07-29 20:49:13

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Oral puzzles

Hi bobbym,

The solution #2421 (Both parts) is correct!  Neat work!

#2422. Water in a canal, 6 meters wide and 1.5 meters deep, is flowing at a speed of 4 kilometers per hour. How much area will it irrigate in 10 minutes, if 8 centimeters of standing water is needed for irrigation?


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

Offline

#3873 2015-07-30 13:04:29

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#3874 2015-07-30 14:26:51

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Oral puzzles

Hi bobbym,

#2423. From the top of a 60 meter high meter building, the angles of depression of the top and the bottom of a tower are 45 degrees and 60 degrees respectively. Find the height of the tower.  Take

.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

Offline

#3875 2015-07-30 20:46:34

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Oral puzzles

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

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