
By: karseng (offline) Sunday, March 18 2012 @ 05:29 AM CDT (Read 1047 times)



karseng 
The ratio of no. of stickers Alex had to the no. of stickers Beng Han had was 1:3. After each of them recieved 25 stickers, the ratio became 3:4. How many stickers did they have altogether at first?

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Registered: 04/20/11 Posts: 3





By: echeewh (offline) Sunday, March 25 2012 @ 08:37 PM CDT



echeewh 
Hey Kar Seng,
The solution is as follows:
(Apply Constant Difference concept  Difference before is same as difference after )
<Before>
A : B Diff
1 : 3 2u
<After>
3 : 4 1u
In order that the difference before and after remain the same, we need to get an equivalent ratio for <After> by multiplying 2x.
6 : 8 2u
Comparing this new <After> ratio to the <Before> ratio, you will see that both A and B has an increase of 5 units each.
Therefore, 5u > 25
1u > 5
Total number of stickers (at first) = 4u > 4 x 5
= 20
============================================
Hope this helps.
Cheers,

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Registered: 04/21/11 Posts: 627





By: karseng (offline) Sunday, March 25 2012 @ 10:29 PM CDT



karseng 

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Registered: 04/20/11 Posts: 3



