Sign Up!
Login
Welcome to Test-paper.info
Friday, July 21 2017 @ 09:44 PM CDT
 Forum Index >  Test Paper Related >  Primary 6 Matters
 SCGS 2008 Prelim Q47
   |  Printable Version
By: mlteo (offline)  Saturday, September 22 2012 @ 10:47 PM CDT (Read 1448 times)  
mlteo

Need help with this question.

Mary had some $5 and $10 notes in her wallet. There was a total of 60 pieces of notes at first.
She used half of the number of $5 notes and received another twelve $10 nots from her mother.
After that, the number of $10 notes she had was 2/3 of the remaining number of $5 notes she
had left.
How much money did she have at first ?

Thanks for any help. Big Grin

Forum Newbie
Newbie


Registered: 12/31/06
Posts: 10

Profile Email    
   
By: echeewh (offline)  Sunday, September 23 2012 @ 07:49 AM CDT  
echeewh

Hey mlteo,

Following pls find my worked solution:

** - used as buffer for alignment.

<After>
* $5 |----------|----------|----------|
$10 |----------|----------|

<Process>
work backwards to develop the <Before> model as follows:
$5 notes: Doubled
$10 notes: -12

<Before>
* $5 |----------|----------|----------|----------|----------|----------|
$10 |----------|--|<12>

Given Total Qty (notes) <before> is 60, we have ...

8u - 12 --> 60
8u --> 60 + 12 = 72
1u --> 9

At first,
$5: 6u --> 6 x 9 = 54
Value: 54 x 5 = $270

$10: 2u - 12 --> (2 x 9) - 12 = 6
Value: 6 x 10 = $60

Total value (at first) = 270 + 60 = $330

========================

Trust this helps.

Do let me know again if there's further clarification.

Cheers,
Edward

Forum Active Member
Active Member

Registered: 04/21/11
Posts: 623

Profile Email    
   
By: mlteo (offline)  Monday, September 24 2012 @ 04:22 AM CDT  
mlteo

Thanks a lot.

You sure made it look so simple.

Some how they always look simple when explained. Big Grin

Forum Newbie
Newbie


Registered: 12/31/06
Posts: 10

Profile Email    
   
By: echeewh (offline)  Monday, September 24 2012 @ 07:33 PM CDT  
echeewh

U re welcome, mlteo.

Actually if you know most of the methods n concepts, I believe one is able to perform better or even excel.

For this question, its only using the basic model concept using <work backwards> method plus the <number x value> method.

Good luck and all the best in your / your child's PSLE.

Cheers,
Edward

Forum Active Member
Active Member

Registered: 04/21/11
Posts: 623

Profile Email    
   


 All times are CDT. The time is now 09:44 pm.
Normal Topic Normal Topic
Locked Topic Locked Topic
Sticky Topic Sticky Topic
New Post New Post
Sticky Topic w/ New Post Sticky Topic w/ New Post
Locked Topic w/ New Post Locked Topic w/ New Post
View Anonymous Posts 
Able to Post 
HTML Allowed 
Censored Content