PSLE Prelim Qn again

[Mightymito]

  On 9/29/2010 at 9:34 AM, Thargor said:

Very Simple lah

 

X = 1/3 of all Ribbons

 

Pink = X number of ribbons

Red = X - 4 ribbons

Yellow = X + 4 ribbons

 

Because Pink = 1/3

So..

 

X + (X+4) - (X-4) = 3X

2X + 8 = 3X

X = 8

 

So Pink is 8 ribbon. Together ribbon is 24.

 

Not correct , you better not be tutoring anybody's daugther

 

First you must find Z4. Is it the teachers time of the month?

 

 

[Thargor]

  On 9/29/2010 at 9:36 AM, Hiphiphoray said:

STILL WRONG!!!

 

Must draw box box one. Cannot use algebra rah.

 

Zero Mark for you.

 

See for yourself lah

[Thargor]

  On 9/29/2010 at 9:42 AM, Mightymito said:

Not correct , you better not be tutoring anybody's daugther

 

First you must find Z4. Is it the teachers time of the month?

 

The answer in the blogspot is wrong by the way....

 

I will teach my daughter to challenge the answer if she think its not right.

[Requiemdk]

  On 9/29/2010 at 9:53 AM, Thargor said:

The answer in the blogspot is wrong by the way....

 

I will teach my daughter to challenge the answer if she think its not right.

 

Dunno about the answer in the blog, but your interpretation of the question is wrong - it says 4 fewer than 1/3 of the REMAINDER are red. You assumed that 4 fewer than 1/3 are red which led to the question being simpler than it actually is. Part of the challenge of the question is to deal with the multiplication of fractions.

[Kxbc]

  On 9/29/2010 at 9:34 AM, Thargor said:

Very Simple lah

 

X = 1/3 of all Ribbons

 

Pink = X number of ribbons

Red = X - 4 ribbons

Yellow = X + 4 ribbons

 

Because Pink = 1/3

So..

 

X + (X+4) - (X-4) = 3X

2X + 8 = 3X

X = 8

 

So Pink is 8 ribbon. Together ribbon is 24.

wrong lah. if pink = 8, then red + yellow = 16.

 

16 cannot be divided by 3 into a whole number. red must be = 1/3 of remainder less 4. Therefore red + yellow must be a number divisible by 3 to get a whole number which is > 4.

Edited September 29, 2010 by Kxbc

[Zniper]

  On 9/29/2010 at 12:57 AM, Tigerwoods said:

The question indicates 4 FEWER THAN 1/3 remaining means this isn't it ??

Why the Solution indicate it to be.

 

Which is correct ??

 

remaining = 2/3 cos 1/3 is pink as stated in the qn...

so hav to use 1/3 * 2/3 = 2/9...

thus u see the (2/9 - 4) in the drawing...

 

cheers...

[Tigerwoods]

  On 9/29/2010 at 6:55 AM, Wind30 said:

yup that was my answer in page one. Basically the total number of ribbons can be 27,36,45 onwards.....multiple of nines. infinite solution. As I said, stupid question.

The answer cannot be 9 (Pink), 2 (Red) and 16 (Yellow).

Because

[Mightymito]

price you pay now for being in the arts stream

[Thargor]

  On 9/30/2010 at 2:08 AM, Mightymito said:

price you pay now for being in the arts stream

 

I have a BA from Arts. But ermmm...I earn more than my peers from Engineering/Sci/ComSci.

 

So they are paying an even higher price for not being in Arts stream huh?

[Mightymito]

they can answer their children's maths questions

[Thargor]

  On 9/30/2010 at 2:15 AM, Mightymito said:

they can answer their children's maths questions

 

And I can afford to hire them to tutor my girl next time...LOL!!!

 

What degree do you have by the way?

Edited September 30, 2010 by Thargor

[Little_prince]

  On 9/30/2010 at 2:14 AM, Thargor said:

I have a BA from Arts. But ermmm...I earn more than my peers from Engineering/Sci/ComSci.

 

So they are paying an even higher price for not being in Arts stream huh?

 

hao lian

[Thargor]

  On 9/30/2010 at 2:24 AM, Little_prince said:

hao lian

Yes, because I can. Can you?

[Enye]

  On 9/29/2010 at 2:45 PM, Tigerwoods said:

The answer cannot be 9 (Pink), 2 (Red) and 16 (Yellow).

Because

 

I cannot understand why the answer cannot be 9P 2R and 16Y, or for that matter of fact any multiples of 3 as long as R is not <=0.

 

 

[Ender]

Only know how to use algebra..

 

Assume total Ribbon to be X.

 

I'm able to derived the following equation for each color

 

Pink = 1/3X

Red = 2/9X-4 (2/9 is derived from 1/3 of remainder, which is 1/3 * 2/3)

Yellow=4/9X+4

 

To satisfy a whole number, X can only be multiples of 9 ( Look at the denominator)

 

Take out spreadsheet, or if your kids are good in mental arithmetics, substitute X with multiple of 9 from 27 onwards.

 

Possible answers starting with X=27

X=27, Pink=9, Red=2, Yellow=16

X=36, Pink=12, Red=4, Yellow=20

X=45, Pink=15, Red=6, Yellow=24 (Teacher's answer, one of the many possible answers)

.............

And so on in mulitple of 9........

.................

Edited September 30, 2010 by Ender

[Invigorated]

Think many of us may be reading too much into this.

 

The questions for PSLE cannot be based on assumptions i.e. minimum value to be taken as answer and is really a lot more straightforward. Even if such qns are posed, there will be parameters given i.e. minimum number.

 

[Hiphiphoray]

Yr nick beri the familar.

 

Are you the one whom pose the arrival of your baby earlier ?

 

So how ? Still manageable bor ? Got Panda eyes liao beh ?

 

  On 9/30/2010 at 2:24 AM, Thargor said:

Yes, because I can. Can you?

 

[Kxbc]

  On 9/30/2010 at 4:33 AM, Hiphiphoray said:

Yr nick beri the familar.

 

Are you the one whom pose the arrival of your baby earlier ?

 

So how ? Still manageable bor ? Got Panda eyes liao beh ?

his baby out long time liao lah. a few months iirc. mtm makeup also cannot remove panda eyes now.