[問題] GWD 12-08

[FionaV]

The figure shown above represents a modern painting that consists of four differently colored rectangles,
each of which has length l and width w. If the area of the painting is 4800 square inches, what is the width,
in inches, of each of the four rectangles?

A. 15
B. 20
C. 25
D. 30
E. 40

Ans: A

這是一個超級笨的問題 但是我怎麼算就是20 可以請大家指點迷津嗎? 謝謝

[panda]

答案是(B)阿...你應該看錯答案了

[jerry7271]

這題似乎很簡單，但我就是求
不出來啊，救命...

(l+w)*l=4800
或
l*w=1200

這兩個我都求不出來啊？

[scujean]

w*l*4=4800,(w+l)*3w=4800
→wl=1200,(w+l)w=1600→wl+W^2=1600
→1200+w^2=1600→w^2=400

[lerry670617]

沒那麼複雜啦
既然題目沒設限你怎麼畫
你就假設是60X80的圖形啊
那寬當然是80啊
分成四等分
當然是20啊

[jerry7271]

感謝啊...
腦筋不夠零活

[chris8888]

我是這樣算的

因為四個rectangles 長l, 寬w都一樣
l * w * 4 = 4800

看那個圖, l = 3w

代進去 3w^2 * 4 = 4800 => w^2= 400 => w=+20 答案B