tianzhu:

tanxexy:

Please help on this question from ACS P5 2014 SA2:


http://i57.tinypic.com/zwe33r.png\">

Hi tanxexy

Good Afternoon

I suggest you get hold of a piece of paper and fold according to picture (no need to be same as dimensions).

This is to get your kid to understand the concept of folded areas or angles.

For this question, imagine you unfold the triangles at the left and right sides to form a square piece of paper of 12cm by 12cm.

Shade the original triangles with colours if you want to.

On the lower side of the square, you’ll see three equal sides of 4cm (12/3).

12 – 5 ----- 7

Area of 1 triangle ----- ½*4*7

Area of 4 triangles ----- ½*4*7*4 ----- 56

Area of square ----- 12*12 ----- 144

Area of shaded parts ----- 144 – 56 ----- 88

Hope this helps.

Best wishes

Hi tianzhu,

Thanks for your help. In fact, I already knew the answer from the guided solutions that came together with the paper. What puzzled me was the basis which concluded that the base is divided equally into 3 (and hence 12/3 = 4cm). I thought there might be some \"tricks of estimation\" taught to Pri sch kids which I am not aware of. I also doubted if the question had some missing info which was only given to the ACS kids during the paper itself. Hence, I posted it out to seek clarification.

And as shared by Ice watch and SAHMom (Thanks to both of you too for chipping in), by PT, it is not exactly 4cm. So I guess we can only agree that this question was not well crafted for a Pri school level.

Thanks to all again for the effort and contributions!

Please help on this question from ACS P5 2014 SA2:


http://i57.tinypic.com/zwe33r.png\">

Jerico:

Hi, can someone pls help with the following question :-


Celest took out 0.3 of her money from her purse. She spent 0.75 of it and had $48 left. She put the money back into her purse. Her mother then gave her $31. How much money was there in her purse finally ?

Thank you in adv for yr help !

Let $x be the the original amount of money in her purse.
$0.3x was taken out, of which she spent 0.75 of it.
Therefore, she was left with 0.25 * 0.3x = 0.075x = $48
=> x = 48/0.075 = $640

$640 * 0.7 = $448 (amount in purse after she took out $0.3x)

Money finally in her purse = $448 + 48 + 31 = $527

Hi,


Shouldn’t it be:

As a result of his hard work, Terence received a salary increment.

2015 PSLE EXAMINATION CALENDAR (TENTATIVE)


Oral Examination Thu, 20 August – Fri, 21 August 2015
Listening Comprehension Fri, 18 September 2015
Written Examination Thu, 01 October – Wed, 07 October 2015
Marking Exercise Mon, 19 October – Thu, 22 October 2015

Note: The examination timetable will be made available by February 2015

Reference: https://www.seab.gov.sg/content/examCal ... r_PSLE.pdf

Jerico:

http://i59.tinypic.com/2hf076v.jpg\">


Kindly help. Thank you very much !

http://i62.tinypic.com/6p6r8w.png\">

Jerico:

Please help with the attached algebra question :-


http://i62.tinypic.com/vpzt5y.jpg\">

Thank you in advance !

(a) From the diagram, the volume of the liquid is 800 cm3.
Volume = Area of Base * Height
=> Area of Base = 800/x

(b) If x = 8, Area of Square Base = 100 cm2
=> Length of Base = Sqrt(100) = 10 cm

tanxexy:

Jerico:

Hi,


Can someone please advise how to solve this problem in more details as I unfortunately do not understand magicpiglet's solution ? Tks.
[quote=\"Jerico\"]Q : Ali and Danny had a total of 108 stickers at first. In
the first game, Ali lost 0.25 of his stickers to Danny. In the second game, Danny lost 2/5 of his stickers to Ali. In the end, they had the same number of stickers left. How many more stickers did Danny have than Ali at first ?

Tks in advance for your help !

[/quote]Hi Jerico,

Here are the model diagrams I try to illustrate magicpiglet's solution:
http://i62.tinypic.com/oib3ic.jpg\">

Hope it is self explanatory.

Jerico:

Hi,


Can someone please advise how to solve this problem in more details as I unfortunately do not understand magicpiglet's solution ? Tks.

Jerico:

Q : Ali and Danny had a total of 108 stickers at first. In
the first game, Ali lost 0.25 of his stickers to Danny. In the second game, Danny lost 2/5 of his stickers to Ali. In the end, they had the same number of stickers left. How many more stickers did Danny have than Ali at first ?

Tks in advance for your help !

Hi Jerico,

We have to work this out backwards. Note the total number of stickers remained unchanged at 108 throughout.

(1) In the end, they had the same =>
108/2 = 54 => They both had 54 at the end.

(2) Before 2nd game
Danny had 54 stickers after he lost 2/5 of them to Ali
=> 54 = 3/5 of his stickers
=> he had (54 x 5/3) = 90 stickers before the 2nd game (which he lost to Ali).
=> Ali had 108 - 90 = 18 stickers before the 2nd game.

(3) Before 1st game
Ali was left with 18 stickers which was 0.75 or 3/4 of his stickers after he lost
=> Ali had (18 x 4/3) = 24 stickers before he lost to Danny in the 1st game
=> Danny had 108 - 24 = 84 stickers at first
=> Danny had 84 - 24 = 60 more stickers than Ali at first

Hope it is clearer to you now.

cheers!

Jerico:

Hi,


Pls help to solve the attached.

Thank you in advance !

http://i57.tinypic.com/25g8os6.jpg\">

Hi Jerico,

Brand A: 4/10 => Brand B & 6/10

Brand B : Brand C = 1 : 3
=> Brand B: 1.5/10 = 3/20
and Brand 4.5/10 = 9/20

Expressing in same denominator, Brand A: 4/10 = 8/20

Let the total number of socks sold be 20u.
In terms of $,
Brand A: 8u x $10 = $80u
Brand B: 3u x $11 = $33u
Brand 9u x $12 = $108u

80u + 33u + 108u = 221u = 3978
=> u = 18

Brand $108 x 18 = $1944
Brand B: $33 x 18 = $594
Brand A: $80 x 18 = $1440
Difference = (1944+594) - 1440 = $1098

cheers!