gmatclub

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gmatclub

by gmat20092009 » Sun Jul 19, 2009 7:20 am
What is the ratio of the area of a TV screen with a diagonal of 18'' to that of a screen with a diagonal of 15''?

1>The ratio of width to length is the same for both screens.
2>The width of the 18''-screen is 20% greater than that of the 15''-screen.


Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient
Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient
EACH statement ALONE is sufficient
Statements (1) and (2) TOGETHER are NOT sufficient



Statement (1) by itself is sufficient. S1 says that the two rectangles are similar. Thus, the ratio of areas = (ratio of respective dimensions)^2.ie (18/15)^2

Statement (2) by itself is sufficient. From S2 it also follows that the rectangles are similar. Ratio of diagonals =18/16 =1.2/1= ratio of widths.

The correct answer is D.

How cum frm B we can find that triangle is similar..pl explain
Source: — Data Sufficiency |

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by real2008 » Tue Jul 21, 2009 10:05 am
anybody there! to explain stmt2?

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Re: gmatclub

by Stuart@KaplanGMAT » Tue Jul 21, 2009 12:58 pm
gmat20092009 wrote:What is the ratio of the area of a TV screen with a diagonal of 18'' to that of a screen with a diagonal of 15''?

2>The width of the 18''-screen is 20% greater than that of the 15''-screen.


How cum frm B we can find that triangle is similar..pl explain
For two shapes to be similar, the angles must be the same and the dimensions must be proportional.

From the original information, we know that the ratios of the diagonals are 18/15 = 1.2/1

From (2), we know that the ratios of the widths is also 1.2/1

Since the triangles also both include a 90 degree angle, we can now conclude that they are similar.
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Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

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