
By: geniuskids (offline) Tuesday, October 16 2012 @ 02:51 AM CDT (Read 919 times)



geniuskids 
Q16 : Mr Chen bought some pencil cases and bags for the children at a gathering.
The price of each pencil case was $2.40 while the price of each bag was $10.80.
For every 4 bags bought, he was given one such pencil case for free.
After receiving the free pencil cases, the number of pencil cases was 1/3 of the number of bags bought.
If Mr Mr Chen paid a total of $1584, how much more did he pay for the bags than the pencil cases?
Thanks

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Registered: 11/12/11 Posts: 169





By: echeewh (offline) Saturday, October 20 2012 @ 07:51 PM CDT



echeewh 
Hey there,
Following pls find my worked solution:
<after> receiving free pencil cases (PC),
PC : B
1 : 3
Given that for every 4 B bought, 1 PC was given free, multiply ratio 4x. (to make B multiple of 4)
PC : B
4 : 12
Apply <Restating the problem> method, we have ..
for 12u of B bought > 3 free PC
PC(bought) : PC (free) : B
1 : 3 : 12
Since total amt paid = $1584 and 1 PC = $2.40 and 1 B = $10.80, we apply <Number × Value> method as shown:
(1u × 240) + (12u × 1080) > 158400
240u + 12960u > 158400
13200u > 158400
1u > 1584 ÷ 132 = 12
PC (bought) = 1u > 12
Value of PC: 12 × 2.40 = $28.80
B = 12u > 12 × 12 = 144
Value of B: 144 × 10.80 = $1555.20
Value of (B  PC) = $1555.20  $28.80 = $1526.40
=====================
Trust this helps.
Do let me know again if there's any clarification.
Cheers,
Edward

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Registered: 04/21/11 Posts: 623





By: geniuskids (offline) Saturday, October 20 2012 @ 08:49 PM CDT



geniuskids 
Thanks Edward. You have been a great hep. Do you mind helping with Q17 Nanyang. Tx

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Registered: 11/12/11 Posts: 169





By: geniuskids (offline) Saturday, October 20 2012 @ 09:06 PM CDT



geniuskids 
latest update: Q17 solved. tks

Active Member
Registered: 11/12/11 Posts: 169



