Welcome to Test-paper.info
Friday, January 19 2018 @ 01:11 PM CST
 Select a Forum » General Chat » Primary 1 Matters » Primary 2 Matters » Primary 3 Matters » Primary 4 Matters » Primary 5 Matters » Primary 6 Matters » Question, Feedback and Comments » Education Classified
 Forum Index >  Test Paper Related >  Primary 6 Matters P6 Hokkien Huay Kuan Prelims 2012 Math Q15
 | Printable Version
 By: Tping (offline)  Wednesday, July 17 2013 @ 11:13 PM CDT (Read 1205 times)
Tping

Cindy, Dick and Eddy had \$410 altogether.
Cindy gave 1/3 of her money to Eddy.
Dick then gave 2/5 of his money to Cindy.
As a result, Dick had \$20 less than Cindy and \$30 less than Eddy.
How much money had Cindy at first?

Junior

Registered: 01/26/12
Posts: 25

 By: echeewh (offline)  Thursday, July 18 2013 @ 04:39 AM CDT
echeewh

Hi <Tping>,

Following is my worked solution:

This question makes use of <Unchanged Total> concept and <Work Backwards> method.

<Unchanged Total> concept means that at the end the total amount that C, D and E had is the same as what they had at first.

*** - for alignment purpose.

<After>

C |------<-20->| ***** -
D |------| ************** | --> \$410 (C+D+E)
E |------<-20-><10>| -

3u --> 410 - 20 - 30 = 360
1u --> 360 ÷ 3 = 120

C: 1u + 20 --> 120 + 20 = \$140
D: 1u --> \$120
E: 1u + 30 --> 120 + 30 = \$150

Use <Work Backwards> method,

<D gave (2/5) of his money to C>
(3/5)D = \$120
(5/5)D = 120 × (5/3) = \$200

C: 140 - 80 = \$60

<C gave (1/3) to E>
(2/3)C = \$60
(3/3)C = 60 × (3/2) = \$90

E: 150 - 30 = \$120

C (at first) = \$90

=========

Trust this helps.

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

Cheers,
Edward

Active Member

Registered: 04/21/11
Posts: 627

 All times are CST. The time is now 01:11 pm.
 Normal Topic Locked Topic Sticky Topic
 New Post Sticky Topic w/ New Post Locked Topic w/ New Post
 View Anonymous Posts Able to Post HTML Allowed Censored Content