uououououo wrote:"Town T has 20,000 residents, 60 percent of whom are female. What percent of the residents were born in Town T?
(1) The number of female residents who were born in Town T is twice the number of male residents who were not born in Town T.
(2) The number of female residents who were not born in Town T is twice the number of female residents who were born in Town T."
This is an EITHER/OR group problem.
Every resident is EITHER male OR female.
Every resident is EITHER born in Town T OR not born in Town T.
To organize the data, use a GROUP GRID (also known as a double-matrix).
Let M=male, F=female, B=born in Town T, NB=not born in Town T.
Since the question stem asks for a PERCENTAGE, let the total number of residents = 100.
Since 60% of the residents are female, the following grid is yielded:
In a group grid, the values in any row or column must add up to the TOTAL of that row or column, as illustrated by the values in the bottom row.
The question asks for the value in the upper right corner: the total percentage born in Town T.
Statement 1: The number of female residents who were born in Town T is twice the number of male residents who were not born in Town T.
The following gird is yielded:
No way to determine the value in the upper right corner.
INSUFFICIENT.
Statement 2: The number of female residents who were not born in Town T is twice the number of female residents who were born in Town T.
The following grid is yielded:
No way to determine the value in the upper right corner.
Statements combined:
The following grid is yielded:
According to the grid, the total percentage born in Town T = 50%.
The correct answer is
C.
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