those were birch trees?

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those were birch trees?

by sanju09 » Wed Jun 29, 2011 3:55 am
The neighborhood association planted 108 new trees last year. How many of those were birch trees?

1. Of all the trees in the neighborhood, 34 percent were birch trees at the end of last year.

2. There were a total of 488 birch trees in the neighborhood at the end of last year.
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by Frankenstein » Wed Jun 29, 2011 4:22 am
Hi,
Clearly, this cannot be solved using either statement alone. If we combine (1)&(2), how can 488 be 34% of an integer. Can you check the values.
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by testprepDublin » Wed Jun 29, 2011 4:44 am
The best way to approach a problem like this is to sketch a quick table. With planted and old trees on one side and birch and non-birch along the top. Now but a question mark in the box corresponding to planted and birch.

S1 gives us the total number of birches but we don't know how many of them were planted last year. Insufficient.

S2 gives us the %of ALL trees which were birch. Not the % of those planted last year.
Insufficient.

S1&S2 tell us about the birches as a subsection of all trees but NOT about those planted last year.
Insufficient.

But there does seem to be conflicting information in the statements. 34%=488 doesn't work as a the number of trees must be an integer.[/img][/list][/list]
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