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Blazing goIITian

Posted on 25 Mar 2009 12:47:50 IST

Topic : PERMUTATION AND COMBINATION SHORTCUTS ------PART 1

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4

3815

Engineering Entrance , JEE Main

1)THE NO. OF PERMUTATIONS OF N THINGS TAKEN TOGETHER WHEN P ARE ALIKE OF ONE KIND, Q OF OTHER TYPE, R OF OTHER     KIND AND REST OF ALL DIFFERENT IS    .       WE MAY CONTINUE IT FOR ANY NUMBER OF ITEMS.2)THE NO. OF PERMUTATIONS OF N DISSIMILAR THINGS, TAKEN ALL AT A TIME    IS (N-1)!3)THE NUMBER OF WAYS OF ARRANGING N DISTINCT OBJECTS ALONG A CIRCLE, WHEN CLOCKWISE AND ANTICLOCKWISE      ARRANGEMENTS ARE CONSIDERED SAME    IS    4)THE NUMBER OF NECKLACES FORMED WITH        N BEADS OF

Dee

Cool goIITian

Posted on 23 May 2010 20:50:33 IST

Topic : Permutations & Combinations - Made Easy

2

1

2310

Engineering Entrance , JEE Main

Permutations and combinationsWhen we talk of permutations and combinations in everyday talk we often use the two terms interchangeably. In mathematics, however, the two each have very specific meanings, and this distinction often causes problems. In brief, the permutation of a number of objects is the number of different ways they can be ordered; i.e. which is first, second, third, etc. If you wish to choose some objects from a larger number of objects, the way you position the chosen objects is also important. With combinations, on the other hand, one does not consider the order in which objects were chosen or placed, just which objects were chosen. We could summar

sathyaram

Blazing goIITian

Posted on 14 Mar 2012 17:41:01 IST

Topic : Ramanujam !

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5

1205

Engineering Entrance , JEE Main

Ramanujam:                                                                                                                                                                   By age 11, he had exhausted the mathematical knowledge of two college students who were lod

amit das

New kid on the Block

Posted on 9 Nov 2011 19:46:46 IST

Topic : shortcut to find the rank of a given word

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1

3174

Engineering Entrance , JEE Main

Shortcut for finding the Rank having words repeated:Rank of AGAIN1     2    1   3     4A    G   A    I     N1st numbers r given to the letters in dictionary orderthen under each letter, write down the number of letters assigned with lesser number occuring towards the right of the letter under which v r writing. 1     2     1     3      4A    G     A      I    &n

prabhat

Cool goIITian

Posted on 19 Jun 2012 11:15:30 IST

Topic : HOW TO FIND ROOTS(IMAGINARY AND REAL )OF A CUBIC EQUATION?????

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1

375

Engineering Entrance , JEE Main

HOW TO FIND ROOTS(IMAGINARY AND REAL )OF A CUBIC EQUATION?????

UNKNOWN *

Blazing goIITian

Posted on 21 Apr 2007 11:14:41 IST

Topic : SET THEORY

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1

2466

Engineering Entrance , JEE Main

   SET THEORYMULTIPLE CHOICE QUESTIONS1. If A = {1, 2, 5} and B = {3, 4, 5, 9}, then A ? B is equal to (a) {1, 2, 5, 9} (b) {1, 2, 3, 4, 9} (c) {1, 2, 3, 4, 5, 9} (d) none of these2. If A = {x: x = 3n, n ? 6, n ? N} and B = {x: x = 9n, n ? 4, n ? N}, then which of the following is false?(a) A U B = {3, 9, 27, 81,243, 729, 6561} (b) A ? B = {9, 81, 729, 6561} (c) A-B = {3, 27,243} (d) A ? D = {3, 27, 243, 6561}3. If Y is the smallest set such that Y U {1, 2} = {1, 2, 3, 5, 9}, then Y is equal to (a) {1,2,3,5,9} (b) {3,5,9} (c) {1,2} (d) none of these4. If n (A) = 115, n (B) = 326, n (A-B) = 47, then n (A U B) is equal to(a) 373 (b) 165 (c) 370 (d) none

viswanathan

Blazing goIITian

Posted on 12 May 2012 12:31:57 IST

Topic : cube root onemore-only for perfect cubes

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3

1116

Engineering Entrance , JEE Main

write the list of cubes of 1-10 as follows1  12  83  274 645 1256 2167 3438 5129 729revise the last numbersknow     pick a perfect cube to check:474552group it by 3 digits,                                       474              552           see the last digit,          &nb

viswanathan

Blazing goIITian

Posted on 10 May 2012 13:58:04 IST

Topic : find the cube root easy technique

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2

1027

Engineering Entrance , JEE Main

General MethodThe divisor should not be too small. The smallness will giverise to big quotients with several digits. This will lead tocomplications.Another method is to multiply the given number by anothersmall number cubed and find the cube root. Final answer iscalculated by dividing the result by small numberExample 4: Find the cube root of 2We multiply 2 by 53The new Number becomes 2 x 125 = 250Find the cube root of 250 and divide the answer by 5 [since we multiplied the original number by 5Step 1250 : 0 0 0By inspection write down 6 and 34 as the first Q and R .Since 216 is the perfect cube close to 250 and thereminder from 250 is 34.Step 2250 : 0 0 0108 : : 34:

boywholived

Scorching goIITian

Posted on 14 Apr 2012 15:12:15 IST

Topic : PLAY WITH GRAPHS

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17

1847

Engineering Entrance , GATE

                        PLAY WITH GRAPHS  Please click like and comment the graph which you like.Try to find some relationship between graphs i.e y=x^2 and sin x and (sin x)^2 .Let your mind and brain blossomTell me the graphs that you want to display   Graph for sin(x) -32-30-28-26-24-22-20-18-16-14-12-10-8-6-4-22468101214161820222426283032 -3.5-3-2.5-2-1.5-1-0.50.511.522.533.5 x: 10.5139131y: -0.88622658       Graph for cos(?x)

Mayank Mittal

Cool goIITian

Posted on 23 Apr 2012 12:01:57 IST

Topic : Modern Einstein Theory of Relativity

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0

1009

Engineering Entrance , GATE

Einstein's Theory of Relativity states that ,  "Agar ek ladke ke haath par kisi ladki ka haath ho to ek ghanta bhi ek minute ki tarah guzarta hai aur agar ek haath ek garam tave pe rakha ho to ek minute bhi ek ghanta ke barabar guzarta hai. "Best Explanation of Albert Einstein's Special Theory of Relativity rate if you like

boywholived

Scorching goIITian

Posted on 22 Apr 2012 17:37:30 IST

Topic : Toughest Problems in The world(must have a look)

2

3

1032

Engineering Entrance , JEE Main

 Source Wikipedia.Don't forget to click like if you find it interestingMillennium Prize ProblemsFrom Wikipedia, the free encyclopedia  This article is about the math prizes. For the technology prize, see Millennium Technology Prize.The seven problems are:The Millennium Prize Problems are seven problems in mathematics that were stated by theClay Mathematics Institute in 2000. As of March 2012, six of the problems remain unsolved. A correct solution to any of the problems results in a US$1,000,000 prize (sometimes called aMillennium Prize) being awarded by the institute. The Poincaré conjecture, the onl

adityamahajan

Cool goIITian

Posted on 14 Apr 2012 11:25:28 IST

Topic : can anyone explain dis..???

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3

677

Engineering Entrance , JEE Main

 if  w is a cube root of unity.. we know dat  1+w+w^2 =0but if we apply A.M>G.M for 1,w,w^2we get thus we get 1+w+w^2 >3so y des two statements contradict????

sathyaram

Blazing goIITian

Posted on 13 Mar 2012 18:35:28 IST

Topic : Factorise!

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1

488

Engineering Entrance , JEE Main

Rationalize the denominator of . With your answer in the form , and the fraction in lowest terms, what is ? Solution: We use the fact that . Let . Then we have:.Thus  (note  are interchangeable), and our answer is . 

sathyaram

Blazing goIITian

Posted on 13 Mar 2012 18:42:19 IST

Topic : Prove

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1

477

Engineering Entrance , JEE Main

 Let  be positive real numbers such that .Prove that: .. Solution: the above expression can be written like   but using am,gm we know that  so we have that  now if we r able to prove that  or  we will be done but on simplifying this we have  or  or  now here set  and we r done........... 

kiler jutt

New kid on the Block

Posted on 11 Mar 2012 18:52:59 IST

Topic : if a+b=1 x a-b=1 y find a,b find x+y find x-y

0

0

496

Engineering Entrance , JEE Main

 find it plzzzif  a+b=1xa-b=1yfind a,bfind x+yfind x-y 

adityamahajan

Cool goIITian

Posted on 12 Feb 2012 12:14:31 IST

Topic : a trick to calculate square of any number orally...

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9

3706

Engineering Entrance , JEE Main

 u can calculate the square of any number dis trick which is based on d following formula- ohkk....so d trick is...let say we have to find the square of 11(m taking a simple example first)..1.v find the nearest multiple of 10 to dat no.....like fr 11 it is 10...for 19 it is 20 and so on........2.now find the difference bw dat multiple of 10 and dat no...and add dat difference to d no of which we have to find d square...ie for 11....difference bw 10 nd 11 is 1..v add 1 to 11=12..3.now multiply d new no which v got by adding d difference(12) with dat nearest multiple of 10 which v found at first step..ie 12x10=1204.now add the square of difference to it...th

hemang

Blazing goIITian

Posted on 26 Jan 2012 09:45:23 IST

Topic : permutations and combinations problems.

2

0

725

Engineering Entrance , JEE Main

/* Style Definitions */table.MsoNormalTable{mso-style-name:"Table Normal";mso-tstyle-rowband-size:0;mso-tstyle-colband-size:0;mso-style-noshow:yes;mso-style-priority:99;mso-style-qformat:yes;mso-style-parent:"";mso-padding-alt:0in 5.4pt 0in 5.4pt;mso-para-margin:0in;mso-para-margin-bottom:.0001pt;mso-pagination:widow-orphan;font-size:11.0pt;font-family:"Calibri","sans-serif";mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:"Times New Roman";mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}Some of the followin

sudhindra shenoy

Blazing goIITian

Posted on 5 Sep 2011 23:03:26 IST

Topic : Practice Questions on Permutation & Combination

4

5

1556

Engineering Entrance , JEE Main

 how many times the digit 7 is written while writing the numbers from 1 to 1,00,00,000? 

hemang

Blazing goIITian

Posted on 18 Jul 2011 18:43:25 IST

Topic : logs without tables !!!!!!!!!!!!

15

21

3683

Engineering Entrance , JEE Main

Easiest Way to Find LOG OF ANY NUMBER WITHOUT USING TABLES This method has been found by a Mr. Satish sharma. This way is applicable only to the common logarithms (i.e. to base 10)  First of all you will have to remember only 4 values.      Log 2 =  0.3010      Log 3 =  0.4771      Log 5 =  0.6989      Log 7 = 0.8450 Let me take an example to illustrate the rest –     Log 945 = Log(9.45 * 10^2)                  = Log(9.45) + Lo

Chinmay Pisu

Cool goIITian

Posted on 16 Nov 2011 11:37:04 IST

Topic : ISAT online reg................

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0

853

Engineering Entrance , JEE Main

  ISAT 2012 online form started from 1 nov.2012IIST is Asia's 1st institute providing education in space science only from undergraduate program upto Ph.D programAfter completing B. tech u must work in ISRO at least for 5 years fees-600/- for OBC(NCL) http://www.iist.ac.in/isat2012/ ISAT2012 www.iist.ac.in

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