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#41976 Re: Help Me ! » Hi » 2005-07-19 22:22:44

There are two types of decimals:- Terminating and recurring.
A number like 12.5 or 1.25 or 3.75 is a terminating decimal.
On the other hand, sometimes, you have numbers like 0.33333333333333.................,
0.166666666666.....................,
1.6666666666666 etc which are called recurring decimals.
For example, 1'/2 or 1/8 is a terminating decimal.
1/3, 5/6 etc are recurring decimals.
I was talking about how recurring decimals are convereted into rational numbers (that is, fractions).
If that is clear, look at the following illustration.
How do we convert 2.166666666666.............. into a rational number?
Let x = 2.16666666666666666............
10 x = 21.66666666666666666..........  ----------(I)
100x = 216.6666666666666666.........  ----------(II)
Subtracting (I) from (II),
90x = 195,
x = 195/90 or 13/6.
Now, have I made myself clear?

#41977 Re: Jai Ganesh's Puzzles » Problems and Solutions » 2005-07-19 21:58:49

#7
The ratio of annual incomes of two persons is 9:7 and the ratio of their annual expenditure is 4:3. Each of them saves $2000 yearly. Find their annual incomes.

#41978 Re: Help Me ! » Difficult question » 2005-07-19 21:56:38

As simple as that!
But you would have to remember
(1) A second is a billion (US) nanoseconds but not a billion (UK) nanoseconds.
and
(2) An American Gallon is different from a gallon in UK

#41979 Re: Jai Ganesh's Puzzles » Problems and Solutions » 2005-07-19 19:25:30

31,100 = S - [500+0.04(s-10,000)]
31,100 = S -[500 + 0.04s - 400]
31,100 = S - 100 - 0.04s
31,200 = 0.96 S
S = 31,200 / 0.96
S = 32,500 smile

#41980 Re: Jokes » Limericks » 2005-07-19 19:14:54

There once was a person called Mathsy...

#41981 Re: Jai Ganesh's Puzzles » Problems and Solutions » 2005-07-19 16:51:33

Problem #6

A salesman's commission is 5% on all sales up to $10,000 and 4% on all sales exceeding this. He remits $31,100 to his parent company after deducting his commission. His sales was worth $_________.

#41982 Puzzles and Games » The truel » 2005-07-19 16:16:11

Jai Ganesh
Replies: 8

Mr. Black, Mr. Gray, and Mr. White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr. Black, who hits his shot 1/3 of the time, gets to shoot first. Mr. Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr. White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr. Black, where should you shoot first for the highest chance of survival? roll

#41983 Re: Maths Is Fun - Suggestions and Comments » Math Is Fun » 2005-07-18 22:00:17

Reminded me of an old joke:-

The European Union commissioners have announced that agreement has been reached to adopt English as the preferred language for European communications, rather than German, which was the other possibility.

As part of the negotiations, Her Majesty's Government conceded that English spelling had some room for improvement and has accepted a five-year phased plan for what will be known as EuroEnglish (Euro for short).

In the first year, 's' will be used instead of the soft 'c'. Sertainly, sivil servants will resieve this news with joy. Also, the hard 'c' will be replaced with 'k.' Not only will this klear up konfusion, but typewriters kan have one less letter.

There will be growing publik enthusiasm in the sekond year, when the troublesome 'ph' will be replaced by 'f'. This will make words like 'fotograf' 20 per sent shorter.

In the third year, publik akseptanse of the new spelling kan be expekted to reach the stage where more komplikated changes are possible. Governments will enkourage the removal of double letters, which have always ben a deterent to akurate speling. Also, al wil agre that the horible mes of silent 'e's in the languag is disgrasful, and they would go.

By the fourth year, peopl wil be reseptiv to steps such as replasing 'th' by 'z' and 'w' by 'v'.

During ze fifz year, ze unesesary 'o' kan be dropd from vords kontaining 'ou', and similar changes vud of kors; be aplid to ozer kombinations of leters.

After zis fifz yer, ve vil hav a reli sensibl riten styl. Zer vil b no mor trubls or difikultis and evrivun vil find it ezi tu understand ech ozer. Ze drem vil finali kum tru. smile

#41984 Re: Puzzles and Games » Test » 2005-07-18 20:17:25

You'd kill me for telling this, but the solution is
that he was born in a hospital in room No.1975
and he died in a hospital in room No.1995. tongue
I never said those were the years, did I? cool

#41986 Re: Jai Ganesh's Puzzles » Problems and Solutions » 2005-07-18 16:52:38

A cistern can be filled by two pipes A and B separately in 45 minutes and 36 minutes respectively. A tap C at the bottom can empty the cistern in 30 minutes. If the tap C is opened 7 minutes after the two pipes A and B are opened, in how many minutes will the cistern be full?

#41987 Re: Puzzles and Games » Test » 2005-07-18 16:48:50

A person was born in 1975 and he died in 1995. He was 25 years of age when he died. How?

(This one's a lateral thinking puzzle big_smile)

#41988 Re: This is Cool » Pick any five... » 2005-07-18 16:30:46

1 20  19
2 19  17
3 18  15
4 17  13
5 16  11
6 15   9
7 14   7
8 13   5
9 12   3
10 11 1

That's 100!

Re-arranging,
1 17  16
2 20  18
3 13  10
4 19  15
5 16  11
6 18  12
7 15   8
8 14   6
9 11   2
10 12  2
100 yet again!

Should it be always (n/2)² for 0 to n??? smile
(Just like the side total of a magic square containing numbers 1 to n² is
(n³+n)/2 ??? smile )

#41989 Re: Jokes » Limericks » 2005-07-18 16:20:26

I once knew someone named justlooking,
Who had a knack for hookin'
Everytime he tried his skill

#41990 Re: Jai Ganesh's Puzzles » Problems and Solutions » 2005-07-17 20:16:17

I um unable to reply. I shall wait for your post and comment on that later, MathsIsFun.

ganesh wrote:

#4 (Without paper, pencil; Time limit : 1 minute)
The sum of three numbers is 174. The ratio of the second number to the third is 9:16 and the ratio of the first number to the third is 1:4. The second number is _______.

Since both the ratios have 4 or a multiple of 4 for C,
the ratio A:B:C = 4:9:16.
The sum of these is 29, and it can be noticed 174 is 29 x 6.
Therefore, the second number is 9 x 6, that is 54.

#41991 Re: Puzzles and Games » Gas Cylinders » 2005-07-17 17:27:14

Ist truck:-    3 full cylinders, 1 half-full and 3 empty
IInd truck:-  2 full cylinders, 3 half-full and 2 empty
IIIrd truck:- 2 full cylinders, 3 half-full and 2 empty

PS:- The Moderator may remove my reply if he/she wants it to be left open.

#41992 Re: Jai Ganesh's Puzzles » Problems and Solutions » 2005-07-17 17:17:01

You are right, Mathsy! smile
#4 (Without paper, pencil; Time limit : 1 minute)
The sum of three numbers is 174. The ratio of the second number to the third is 9:16 and the ratio of the first number to the third is 1:4. The second number is _______.

#41993 Re: Help Me ! » Hi » 2005-07-16 17:43:13

Jenilia, we shall prepare you for the Olympiad;
I shall start with my first lesson,
do you know how recurring decimals are converted into fractions?
Lets assume x=0.1414141414....................
100 x = 14.14141414.....................
Deducting equation (2) from (1),
99x = 14
x = 14/99

#41994 Re: This is Cool » Solve this! » 2005-07-16 17:39:38

Mathsy, you are, I repeat, you are, really smart! smile

#41995 Re: Jai Ganesh's Puzzles » Problems and Solutions » 2005-07-16 00:24:18

I saw this problem and I was impressed. I didn't know someone had posted a similiar problem earlier. Okay, I shall give the solution and post a new problem instead.
The solution :- 6 /(1-3/4)


The new problem #3
Imagine you are writing numbers from 1 to 1000 on a piece of paper. How many times would you write the number'9'? tongue

#41996 Re: This is Cool » Solve this! » 2005-07-16 00:13:57

tt is, relatively, a newcomer, and he /she solves my problems quickly. cool
I had requested this member to wait for the others to post their replies, maybe he/she thought this was unanswered for quite some time. cool

#41997 Re: Jai Ganesh's Puzzles » Problems and Solutions » 2005-07-16 00:06:12

I shall try to solve that when I start the next week,
here's my problem for the day roll

Using the numbers 1, 3, 4, and 6, together with the operations +, -, ×, and ÷, and unlimited use of brackets, make the number 24.  Each number must be used precisely once.  Each operation may be used zero or more times.  Decimal points are not allowed, nor is implicit use of base 10 by concatenating digits, as in 64 - 31.

#41998 Re: Puzzles and Games » Test » 2005-07-15 23:08:39

I am unable to guess why she did it!

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