
By: tangara (offline) Tuesday, August 02 2011 @ 11:30 PM CDT (Read 2139 times)



tangara 
Hi expert,
I have attempted Ai Tong's SA 2 the following question but I am still clueless how to get the answer.
Even though there's model answer behind but I am still stuck why 2 sticker = 1 unit.
Hope someone can explain to me. Thanks.
If Vera gives Bala 2 stickers, he will have the same number of stickers as Vera.
If Bala gives Vera 2 stickers, Vera will have 5 times as many stickers as Bala.
How many stickers does each of them have?

Junior
Registered: 07/31/10 Posts: 26





By: YTNg (offline) Wednesday, August 03 2011 @ 04:35 AM CDT



YTNg 
When Vera gives Bala 2 stickers,
she will have the same number of stickers as Vera,
means Vera has 4 more stickers than Bala.
If Bala gives 2 stickers to Vera,
Vera would have 8 more stickers than Bala
This 8 stickers will make up 4 times as Vera is now having 5 times as many stickers as Bala.
4 units = 8 stickers
1 unit = 2 stickers.
Ans: Vera : 8 stickers
Bala: 4 stickers.
Hope the above is correct.[file]

Newbie
Registered: 12/31/06 Posts: 7





By: tangara (offline) Wednesday, August 03 2011 @ 09:45 AM CDT



tangara 
Thanks for your kind reply again. Really appreciate your help.
My question is why the model is drawn such that Vera and Bala have 2 units initially?
Why not 1 : 1 for Vera and Bala?

Junior
Registered: 07/31/10 Posts: 26





By: YTNg (offline) Wednesday, August 03 2011 @ 08:31 PM CDT



YTNg 
My concern is since Bala is going to give away some of his stickers later on, and he will be left with 1 unit compares to 5 as Vera, if we draw model of 1:1, Bala will
have a fraction of 1 unit in the end.
If we start with 2:2, it will be easier to manage later on.
Feel free to point out my mistake as I'm also in the learning stage.

Newbie
Registered: 12/31/06 Posts: 7





By: cimman (offline) Monday, August 22 2011 @ 12:44 PM CDT



cimman 
this belongs to a category of question call Internal Transfer with Unchanged Total Concept.
best explained with a model drawing. As I'm unable to draw the model here, I can only refer you to the book "Challenging Maths Problems Made Easy", by Ammiel Wan Chee Hong. Marshall Cavendish publisher. Can be found in Popular Bookstore.
There is a similar problem at page 69, Question 8 of the book. Check out the model solution to this problem at the end of the book. It is very clear and concise.
Have your child work out similar problems from this book and your child will be an expert on this kind of problems.

Newbie
Registered: 05/01/11 Posts: 5



