PERFECT NUMBER

In mathematics, a perfect number is defined as a positive integer which is the sum of its proper positive divisors, that is, the sum of the positive divisors not including the number itself. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors, or σ(n) = 2 n.
Example:
The factors of 6 are 1, 2, 3 and 6.1 + 2 + 3 = 6 = 2^ (2-1)*(2^2 – 1)
The factors of 28 are 1, 2, 4, 7, 14 and 28.1 + 2 + 4 + 7 + 14 = 28.
28 = 2^ (3-1)*(2^3 – 1)
The factors of 496 are 1, 2, 4, 8, 16, 31, 62, 124, 248 and 496.1 + 2 + 4 + 8 + 16 + 31 + 62 + 124 + 248 = 496.
496= 2^ (5-1)*(2^5 – 1)
The factors of 8128 are 1, 2, 4, 8, 16, 32, 64, 127, 254, 508, 1016, 2032, 4064 and 8128. I'll let you add them up.
8128= 2^ (7-1)*(2^7 – 1)
Formula to calculate Perfect Number:
Perfect Number = 2^ (n-1) * (2^n - 1)
Where n and 2^n – 1 has to be prime numbers.
Note: It is not necessary that when n is prime 2^n – 1 is always prime.
Put n = 11, 2^11 – 1 = 2047= 23*89 .

Peeeeeeeeeeeeeeeeep IN

English, for sure, is a funny language. Here if you want to guess the word meanings your old friend ‘intuition’ might not be able to help you always. Here are few words that would highlight the funny aspect of VOCABULARY in English.

PERCHANCE has nothing to do with chance, it means perhaps.

Though PERCOLATE is to move gradually through a surface with small holes or spaces in it, PERCOLATOR simply means a pot for making coffee.

A PRODIGY is a young person who is unusually intelligent or skilful for his age, while PROTÉGÉ is a young person who is helped in his career and personal development by a more experienced person.

PROPRIETY means correct behaviour, strangely PROPRIETOR is the owner of a business, a hotel etc.
Keep watching this space to master vocabulary the fun and more interesting way

A Few things you should know about Google...Part 1

Being in awe of this new age creature called Google, I thought I should share the few things about Google with you all...

Apart from being the Search King of the world, there are a lot of other things that Google brought to this world. Sample this:

Google Docs- a sure competitor to Microsoft Office Suite, though there is still some long way to go. But check out the sharing features in Google Spreadsheets, and you will never have to use email attachments. Take this one-minute Survey that I created in the other window even as I was writing this blog piece. To participate, just click on this link:

http://spreadsheets.google.com/viewform?key=p1noMdNLLVAUKuMzMMAxLHQ&email=true

I hope you didn't miss the comments left by other people in the poll. And that's real time!

I find this truly exciting because it gives common men and women the power to communicate, and get opinions from others. I have seriously thinking about using this to get student feedback. Do you think it would work? I will try and capture your answer to this question in a separate form :)

I will try to keep you updated about the other exciting stuff (and there is a lot of it, believe me!)

DI....

Refer to the caselet below and answer the questions.
In the new version, Sholay 2006, Amitabh, Dharmendra, Manmohan, Jhonny Lever, Manoj Vajpayee, and Rahul Bose play the roles of Surma Bhopali, Samba, Thakur, Gabbar Singh, Veeru and Jay, though not respectively. All will wear different coloured dresses, i.e. black, blue, green grey, khaki and white.Johnny Lever and Rahul Bose will not play the role of Thakur and Samba. Gabbar Singh will wear khaki but his role will not be played by Manoj Vajpayee or Dharmendra. Amitabh and Manmohan will play the role of Samba and Jay though not respectively. The green-dressed actor and Manoj Vajpayee will play the role of Veeru and Thakur though not respectively. The role of white-dressed Jay and black-dressed Surma Bhopali will not be played by green-dressed Dharmendra and grey-dressed Manoj Vajpayee. Rahul Bose and Manmohan will wear neither black nor white dress.

1. Dharmendra plays the role of
a) Thakur b) Samba c) Veeru d) Data inadequate

2. Who wears the khaki dress?

a) Rahul Bose b) Johnny Lever c) Manmohan d) Data inadequate

3. The role of Surma Bhopali will be played by

a) Johnny Lever b) Rahul Bose c) Manmohan d) Data inadequate

4. Who plays the role of Gabbar Singh?

a) Johnny Lever b) Rahul Bose c) Dharmendra d) Can't be determined

solve it....

An archaelogist was excavating a site in France where he comes upon 4 lettered english word, he made an entry in his notebook and found that word is of french origin.
Further he noticed that if u replace letters with its alphabetical position( a=1, b=2 and so on)
Sum of all digits ends up to 20. Again he found that addition of any three digits is always devisible by fourth digit.

Find the word?

Check your aptitude

Check your aptitude by solving following 10 Questions in 20 minutes.
1 An orange glass has orange juice and white glass has apple juice both of equal volumes. 50 ml of the orange juice is taken and poured into the apple juice. 50 ml from the white glass is poured into the orange glass. Of the two quantities, the amount of apple juice in the orange glass and the amount of orange juice in the white glass, which one is greater and by how much?

2 A family X went for a vacation. Unfortunately it rained for 13 days when they were there. But whenever it rained in the mornings, they had clear afternoons and vice versa. In all they enjoyed 11 mornings and 12 afternoons. How many days did they stay there totally?

3 There is one lily in the pond on 1st june. There are two in the pond on 2nd june . There are four on 3rd june and so on. The pond is full with lilies by the end of the june.(i) On which date the pond is half full?

4 A lorry starts from Banglore to Mysore at 6.00 A.M, 7.00 A.M, 8.00 am.....10 pm. Similarly one another starts from Mysore to Banglore at 6.00 am,7.00 am, 8.00 am.....10.00pm. A lorry takes 9 hours to travel from Banglore to Mysore and vice versa.(i) A lorry which has started at 6.00 am will cross how many lorries.

5 A theif steals half the total no of loaves of bread plus 1/2 loaf from a backery. A second theif steals half the remaining no of loaves plus 1/2 loaf and so on. After the 5th thief has stolen there are no more loaves left in the backery. What was the total no of loaves did the backery have at the beginning.

6 The Old car of Mary requires tyres to be changed after each 24000 km. If she wants to go for 42000 km journey then how many minimum number of tyres she will need.

7 Alice and Liu had some berries. The total of Alice's berries and square of number of berries with Liu is 62. The total of Liu's berries and square of number of berries with Alice is 176. How many berries does each of them have?


8 A begger collects cigarette stubs and makes one full cigarette with every 7 stubs. Once he gets 49 stubs. How many cigarettes can he smoke totally?

9 Person spending out 1/3 for cloths, 1/5 of the remaining for food and 1/4 of the remaining for travels. He is left with Rs 100/-. How he had in the beginning

10 A can build a wall in 30 days; B can demolish the wall in 40 days. If A and B working on alternate days when will be the first time wall will be completely build.
Note: For analyzing your aptitude reply these questions.