
By: mumof2boys (offline) Saturday, May 05 2012 @ 02:09 AM CDT (Read 1390 times)



mumof2boys 
This problem is similar to the last one about Adam and Tom.
Mr Zaini has a carton with red and green apples. If he adds 10 red apples, 0.6 of the total will be green apples. If he adds in 30 green apples, 3/4 of the total apples will be green. How many apples are there in the carton? Is there a simpler way to answer it than U and P used in the previous solution?
Thanks.

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Registered: 08/22/09 Posts: 6





By: geniuskids (offline) Saturday, May 05 2012 @ 08:16 AM CDT



geniuskids 
Can I know which section and the question no?tx

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Registered: 11/12/11 Posts: 169





By: mumof2boys (offline) Sunday, May 06 2012 @ 04:51 AM CDT



mumof2boys 
it's Paper 2, no. 18. I could solve it using parts and units. just want to know if there is any other way to do it?

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Registered: 08/22/09 Posts: 6





By: echeewh (offline) Monday, May 07 2012 @ 10:17 PM CDT



echeewh 
Hey mumof2boys,
Im not sure if your method using parts n units is the same as my solution by model method. In Maths sometimes there can be more than 1 approach to the question itself. Since you are seeking another method besides parts n units ( which i believe is using model concept ), we can use the Simultaneous concept here. This is how it works.
To arrive to this <Before> model for the R apples, we need to subtract 10 from the 4p.
<Before>
G: 6p
R: 4p  10
<Process>
Add 30 G
<After>
G: 3u
R: 1u
6p + 30 > 3u  (1)
4p  10 > 1u  (2)
Since question is asking for number of apples in carton at start, we shall eliminate (u). So ...
(2) x 3: 12p  30 > 3u  (3)
Compare (3) with (1), subtracting (1) from (3) will eliminate (u).
(3)  (1): 12p  6p  30  30 > 0
6p > 60
1p > 10
Hence, number of apples in carton (at start) = 10p  10 > ( 10 x 10 )  10 = 90
==================================
Trust the above helps.
Cheers,
Edward

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Registered: 04/21/11 Posts: 625



