Imagine you are in a big house and you need to match out the 3 switches located in the first floor with the three light bulbs located in the ground floor. In the ground floor there are 3 bulbs (all are off at the moment), each switch belongs to some bulb.

Question

How can you find out, which switch belongs to which bulb?

Other conditions

It is impossible to see from one room to another.

He can only get down only once to check out the bulb.

Only hands are used. No other device.

Leave your answers below as comments.

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At the beginning of the twentieth century, when there was a great interest in the Sanskrit texts in Europe, Bharati Krsna Swamiji tells us some scholars ridiculed certain texts which were headed 'Ganita Sutras'- which means mathematics. They could find no mathematics in the translation and dismissed the texts as rubbish. Bharati Krsna Swamiji, who was himself a scholar of Sanskrit, Mathematics, History and Philosophy, studied these texts and after lengthy and careful investigation was able to reconstruct the mathematics of the Vedas. According to his research all of mathematics is based on sixteen Sutras, or word-formulae.

Bharati Krsna wrote sixteen volumes expounding the Vedic system, which you can find in the book named Vedic Mathematics by Bharati Krsna Tirthaji. These sutras were unaccountably lost and when the loss was confirmed in his final years he wrote a single book: Vedic Mathematics, currently available. It was published in 1965, five years after his death. The term Vedic Mathematics now refers to a set of sixteen mathematical formulae or sutras and their corollaries derived from the Vedas.

You can find more details about Origin of Vedic Maths here at wikipedia - http://en.wikipedia.org/wiki/Bharati_Krishna_Tirtha's_Vedic_mathematics

Related posts:

1. Vedic Mathematics Techniques for Finding HCF
2. Vedic Mathematics Course
3. Benefits of Vedic Mathematics

A man on a park bench is looking at a small portrait. You ask him, Who is that in the picture?
The man says, Brothers and sisters, I have none, but that man's father, is my father's son.
Can you tell what person is in the picture?

A beggar's brother died, but the man who died had no brother. How could this be?

Leave your answers below as comments. If you have more such puzzles based on family relationships, post them as comments below.

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2. Eureka Puzzle
3. A beggar’s brother died

Your grandfather, determined to start the year 1900 off right, went to bed at 7 p.m. on December 31, 1899, setting his alarm clock to wake him at 8 the next morning. He slept like a log. How many hours sleep did he get?

Ancient Coin Puzzle

A thief went to a shop that sold antique coins. He stole a coin from Emperor Alexander’s time that had 326 B.C. inscribed on it. These rare coins were worth $ 100 for every year of their age (years from date of minting till now). So how much did the thief get for his stolen coin?

Both the puzzles above have some similarity. There is a clue hidden in the title of the post itself.

Related posts:

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2. You have 12 coins, one of which is fake.
3. You have a pile of 24 coins

Timing Puzzle 1
Having 2 sand-glasses: one 7-minute and the second one 4-minute. How can you time correctly 9 minutes ?

Timing Puzzle 2
A teacher of mathematics used an unconventional method to measure a 15-minute time limit for a test. He just used 7 and 11-minutehourglasses. During the whole time he turned sandglasses only 3 times (turning both hourglasses at once count as one flip).

Explain how the teacher measured 15 minutes.

Leave your answers below

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2. Stolen Tyre!!!!
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Long Division reduced to one-line shortcut

Example 1:  716769 ÷ 54.

Reduce the divisor 54 to 5 pushing the remaining digit 4 “on top of the flag” (Dhvajanka so to say).

Corresponding to the number of digits flagged on top (in this case, one), the rightmost part of the number to be divided is split to mark the placeholder of the decimal point or the remainder portion.

Let us walk through the steps of this example:
716769 ÷ 54 = 13273.5

1. 7 ÷ 5 = 1 remainder 2. Put the quotient 1, the first digit of the solution, in the first box of the bottom row and carry over the remainder 2
2. The product of the flagged number (4) and the previous quotient (1) must be subtracted from the next number (21) before the division can proceed. 21 - 4 x 1 = 1717 ÷ 5 = 3 remainder 2. Put down the 3 and carry over the 2
3. Again subtract the product of the flagged number (4) and the previous quotient (3), 26 - 4 x 3 = 1414 ÷ 5 = 2 remainder 4. Put down the 2 and carry over the 4
4. 47 - 4 x 2 = 3939 ÷ 5 = 7 remainder 4. Put down the 7 and carry over the 4
5. 46 - 4 x 7 = 1818 ÷ 5 = 3 remainder 3. Put down the 3 and carry over the 3
6. 39 - 4 x 3 = 27. Since the decimal point is reached here, 27 is the raw remainder. If decimal places are required, the division can proceed as before, filling the original number with zeros after the decimal point27 ÷ 5 = 5 remainder 2. Put down the 5 (after the decimal point) and carry over the 2
7. 20 - 4 x 5 = 0. There is nothing left to divide, so this cleanly completes the division

Example 2:  45026 ÷ 47

Reduce the divisor 47 to 4 pushing the remaining digit 7 “on top of the flag” (Dhvajanka so to say).

Corresponding to the number of digits flagged on top (in this case, one), the rightmost part of the number to be divided is split to mark the placeholder of the decimal point or the remainder portion.

Let us walk through the steps of this example:

45026 ÷ 47 = 958.0

1. 4 ÷ 4 = 0 remainder 4. Put the quotient 0, the first digit of the solution, in the first box of the bottom row and carry over the remainder 4
2. The product of the flagged number (7) and the previous quotient (0) must be subtracted from the next number (45) before the division can proceed. 45 - 7 x 0 = 4545 ÷ 4 = 9 remainder 9. Put down the quotient 9 and carry over the remainder 9.
3. Again subtract the product of the flagged number (7) and the previous quotient (9), 90 - 7 x 9 = 2727 ÷ 4 = 5 remainder 7. Put down the quotient 5 and carry over the remainder 7.
4. 72 - 7 x 5 = 3737 ÷ 4 = 8 remainder 5. Put down the quotient 8 and carry over the remainder 5.
5. 56 - 7 x 8 = 0there is nothing left to divide, so this cleanly completes the division.

In reply to the query of Pratiush

To divide 716769 by 156:  Split divisor as 15 and 6

---------------------     11        17       12             12      15        9

15 6               71         6          7         6               9        0        0

----------------- 4         5          9         4               6        7        3

Answer:  4594.673

Remarks:  In the first step we have written that 4 ÷ 4 = 0 remainder 4 instead of 4 ÷ 4 = 1 remainder 0. Otherwise, in the following step, we would have to subtract 7*1=7 from 05 which is not possible.

This post is contributed by Nandeesh Nagarajaia. He is a Chemical Engineer who did his B.Tech from NIT Suratkal.  He is now in IT field as Assistant General Manager(Systems) in Hindustan Copper Limited.

Other guest posts by Nandeesh -

1. Quick Method to evaluate polynomials - Horner's Method
2. Quick calculations for extremely large numbers
3. Shortcut multiplication for approximate numbers
4. Heron's method of finding roots

Related posts:

1. Vedic Division by Nine
2. Divisibility Rules for 7 , 11 and 13
3. Decimal Fraction Rules

This was a statement I heard many times while interacting with students preparing for competitive examinations including CAT. This was in response to my appeal to them to memorize tables up to 20x20.

Today I am posting here on QuickerMaths.com, the method which I recommend to my students too.

How to multiply up to 20x20 in your head?

Assumption: You know your multiplication table reasonably well up to 10×10.

I am trying to explain this with an example,

Say you want to multiply - 16 x 13

Step 1 – Add the unit’s digit of one to the other number –

Here, add 16 + 3 = 19

Or, add 13 + 6 = 19

Step 2 – Put a zero after the number (i.e. multiply it by 10)

Here, 19 becomes 190

Step 3 – Multiply unit’s digit of both the numbers

Here, 6x3 = 18

Step 4 – Add the product to the result of Step 2

Here, 190 + 18 = 208

Simple!! Isn’t it?

Another example, 17x19 =  (17+9)*10 + (7*9)  = 260 + 63 = 323

(10+a) * (10+b) = 100 + 10b + 10a + a*b
= (10+a+b) * 10 + a*b
==========
This can be extended to sums like 23 * 28
(20+a) * (20+b) = 400 + 20b + 20a + a*b
= (20+a+b) * 20 + a*b
So, 23*28 = (23+8)*20 + 3*8 = 620 + 24 = 644.
==========
& so on.

by NANDEESH H N

Try for yourself. Let me know (by posting a comment below) if you liked it.

Click here for some more fast multiplication tricks

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So here I go. This is regarding the name of the website - QuickerMaths.com. It is inspired by the name of the best mathematics books I have ever come across. This book helped me a lot in clearing CAT and reaching to IIM. The inspiration of creating an interactive platform (QuickerMaths.com) came from this book. As a token of appreciation and to do my bit today I will tell you about this book named -

Magical Book on Quicker Maths

Author: M. Tyra

About the book: The book will be a boon for the aspirants of today’s competitive exams irrespective of their background – whether they come from arts, science or commerce stream. Concepts have been clarified so well, that even if one is vaguely familiar with them as in the case of non-mathematics students, understanding will not be a problem. Direct formulae are beneficial for one and all. They save time and time is precious for everyone.

Must for Competitive Preparation

The book is profusely illustrated. Avoiding the temptation for haste and ending up with a cookbook, the author has put in two years of intensive effort and research. Ideas have been taken from available study material, number theory, readers’ suggestions and, finally Vedic mathematics.

Recently I purchased the latest edition of this book from online book store Flipkart.com

Purchase Online

Those who have already read this book please give your feedback to help others.

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Today I thought it might be fun to do a bit of a fun challenge.

The challenge is very simple – You have to find the websites, blogs, web pages, etc. linking to QuickerMaths.com (QM) or any of its post.

As your answers you have to just paste the URL (link) of the website or blog where you have seen QM link.

Rules:

1. The link might be a blogroll link like the one in the image below on fireup blog

2.  Link within the text referring to QM. That could be because someone copied any post from QM and pasted it elsewhere.

The figure below shows an example of this on forum of www.caclubindia.com

1. The link can be on a social networking site like facebook, orkut, etc. posted by you or someone else.
2. The link could be a simple mention of the link - http://www.quickermaths.com or www.quickermaths.com or quickermaths.com

(But it should be a link and not simple text)

*You can even give the link of websites or blogs where you yourself have give QM’s link. When you posted the link doesn’t matter.

**Links present on QuickerMaths.com website will not be considered.

I assure you it will be a fun filled experience and your “googling” skills will improve a lot.

The winner will get the most amazing book on Vedic Mathematics by the father of Vedic Maths - Bharati Krsna Tirthaji Maharaja

Vedic Maths book

To know more about the book – visit http://vedicmathsindia.org/view_detail1.htm

While giving your responses as comment below –

• Mention your full name in name space
• Mention your email address in email space
• Mention http://www.quickermaths.com in the website space

I will collect the address after announcing the winner to send the prize.

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To appreciate the Vedic Maths process of finding the HCF you first need to know the other methods taught in school. I am giving you two other methods to compare with.

Example 1: Find the H.C.F. of x^2 + 5x + 4 and x^2 + 7x + 6.

Example 1: Find the H.C.F. of x^2 + 5x + 4 and x^2 + 7x + 6.

1. Factorization method:x^2 + 5x + 4 = (x + 4) (x + 1)

x^2 + 7x + 6 = (x + 6) (x + 1)

H.C.F. is ( x + 1 ).

2. Continuous division process.

x^2 + 5x + 4 ) x^2 + 7x + 6 ( 1

x^2 + 5x + 4___________2x + 2 ) x^2 + 5x + 4 ( ½x

x^2 + x__________4x + 4 ) 2x + 2 ( ½2x + 2______0
Thus 4x + 4 i.e., ( x + 1 ) is H.C.F.

Now see Vedic Maths way of finding HCF of 2 algebraic expressions.

i.e. x+1 is the HCF

Isn't it much simpler than the above 2 methods.

Now see some more examples -

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