spoud74 Posted February 14, 2007 Share Posted February 14, 2007 One person has a fence, and he uses the fence for a rectangle area, and the length is twice longer than the width. if he uses the fence for a square, the area will be 400 feet bigger. how long is the fence? 1). 16 2). 40 3). 160 4). 1200 5). 1600 Rectangle width = x Rectangle length = 2x Rectangle perimeter = 2(x+2x) = 6x If legth of 6x is to be used for a square then each side of the sqare will be of length 6x/4 = 3x/2 Area of Square = (3x/2)^2 Area of rectanlge = 2x^2 (9/4)x^2 - 2x^2 = 400 (1/4)x^2=400 x=40 Length of fence = 6(40) = 240 :doh: Not one of the answer choices. I am not sure where I went wrong in my assumptions. Would appreciate a double check. Quote Link to comment Share on other sites More sharing options...
ravindra_iit Posted February 14, 2007 Share Posted February 14, 2007 I think both the highlighted portions don't match! length = 3x! One person has a fence, and he uses the fence for a rectangle area, and the length is twice longer than the width. if he uses the fence for a square, the area will be 400 feet bigger. how long is the fence? 1). 16 2). 40 3). 160 4). 1200 5). 1600 Rectangle width = x Rectangle length = 2x Rectangle perimeter = 2(x+2x) = 6x If legth of 6x is to be used for a square then each side of the sqare will be of length 6x/4 = 3x/2 Area of Square = (3x/2)^2 Area of rectanlge = 2x^2 (9/4)x^2 - 2x^2 = 400 (1/4)x^2=400 x=40 Length of fence = 6(40) = 240 :doh: Not one of the answer choices. I am not sure where I went wrong in my assumptions. Would appreciate a double check. Quote Link to comment Share on other sites More sharing options...
spoud74 Posted February 14, 2007 Author Share Posted February 14, 2007 ravindra_iit, if I suppose that rectangle length = 3x, then solving for the perimeter, I get 160 which is one of the answer choices. I am having trouble though translating the question to the point which says: l = 3x w = x To me it sounds like the question is saying l = 2x w = x Anyone else care to provide an opinion? Quote Link to comment Share on other sites More sharing options...
ravindra_iit Posted February 15, 2007 Share Posted February 15, 2007 'the length is twice longer than the width' ==> l = w + 2w = 3w 'the length is twice the width' ==> l = 2w do you have the OA? is it 'C'? Quote Link to comment Share on other sites More sharing options...
spoud74 Posted February 15, 2007 Author Share Posted February 15, 2007 Yes, OA seems to be 160. Quote Link to comment Share on other sites More sharing options...
sunilsm28 Posted February 16, 2007 Share Posted February 16, 2007 The equation seems to be wrong spoud. its 3W..solving it comes out 160 Quote Link to comment Share on other sites More sharing options...
jvujuc Posted February 19, 2007 Share Posted February 19, 2007 What is the source of this question? Quote Link to comment Share on other sites More sharing options...
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