
By: Tping (offline) Wednesday, July 17 2013 @ 11:13 PM CDT (Read 1160 times)



Tping 
Hi, please help..
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?
Thank you in advance.

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: 625



