
By: Tping (offline) Thursday, June 07 2012 @ 03:25 AM CDT (Read 1699 times)



Tping 
Hi, pls help,
Mr Ang bought a total of 200 pears and apples at $0.20 each.
5 apples were rotten.
He sold the pears at $0.70 each and the apples at $0.35 each.
He earned $58 after selling his fruits.
How many apples did Mr Ang buy?
Thank you!

Junior
Registered: 01/26/12 Posts: 25





By: echeewh (offline) Thursday, June 07 2012 @ 09:38 AM CDT



echeewh 
Hey there,
Following pls find the worked solution:
Let there be 1u of A and 1p of P
Total Cost of (1u + 1p = 200) A,P = 200 x 0.20 = $40
Using Number x Value method, we have ...
(converting money to cents)
(1u x 20) + (1p x 20) > 4000
20u + 20p > 4000
2u + 2p > 400  (1)
After 5A were found to be rotten, the remaining fruits were sold at a profit of $58. I.e. these fruits were sold at $98.
Remaining fruits (in units and parts)
A: (1u  5)
P: (1p)
[(1u  5) x 35] + (1p x 70) > 9800
35u  175 + 70p > 9800
35u + 70p > 9975
1u + 2p > 285  (2)
Given that question is interested in apples (u), we eliminate pears (p) as follows:
(1)(2): 1u > 400  285 = 115
================================================
Trust this helps.
Cheers,
Edward

Active Member
Registered: 04/21/11 Posts: 627





By: awyw1201 (offline) Thursday, June 07 2012 @ 10:05 AM CDT



awyw1201 
Another approach using supposition
Cost of all fruits200 x $0.20=$40
No. Of fruits sold2005=195
Selling price of all 195 fruits$40+$58=$98
Suppose all fruits sold were apples, we have
195 x $0.35=$68.25
Diff$98$68.25=$29.75
Doff btw 1 pear and 1 apple$0.70$0.35=$0.35
No. of pears$29.75/$0.35=85
No.of apples at first19585+5=115

Regular Member
Registered: 07/08/11 Posts: 87





By: echeewh (offline) Thursday, June 07 2012 @ 02:22 PM CDT



echeewh 
hi there,
FYI, pls do not take a risk with Guess n Check or Assume ALL method if there is a proper method in solving the problem.. You may not get the full method marks allocated. Hence its to your disadvantage.
Thank you,
Edward

Active Member
Registered: 04/21/11 Posts: 627





By: awyw1201 (offline) Friday, June 08 2012 @ 11:12 AM CDT



awyw1201 
Quote by: echeewhhi there,
FYI, pls do not take a risk with Guess n Check or Assume ALL method if there is a proper method in solving the problem.. You may not get the full method marks allocated. Hence its to your disadvantage.
Thank you,
Edward
Hi Edward, as I mentioned in the other thread, there is no deduction of marks for the assumption method. Please do get your facts right before u post. Thanks.

Regular Member
Registered: 07/08/11 Posts: 87





By: echeewh (offline) Saturday, June 09 2012 @ 05:03 PM CDT



echeewh 
Hey awyw1201 ( to whom it may concern )
I have to agree to disagree ...
Whether or not I get my facts right, yes of course I do. I have seen different marking schemes from about 10 or more schools and encountered situation in which 0 mark is given for Guess& Check / Assume ALL method used in questions where correct / 'proper' method(s) can be used.
Hence, I find its important to share this out with parents and students concerned. Again, whether 0 mark is awarded or not, depends very much on the marker and/or school. My advice is use other correct methods first and take this as a final resort. Exception is to use this method for those typical kind of questions ( where such methods are used ). Again, its always to be 'safe than sorry'. Morale of the story is 'dont take risk' / 'never take chances' like this as it may cause you 0 Method marks, and the opportunity to get a better score that may lead to a better grade.
To All concerned: Pls take this a word of caution and I shall leave this matter in your own hands ( for you to decide ).
Cheers,
Edward

Active Member
Registered: 04/21/11 Posts: 627



