Re: [計量] 兩題計量請教
※ 引述《audition (死得痛快又痛又快)》之銘言:
: 1.
: The decorating committee for a dance plans to fringe
: the 3-inch-wide end of a streamer by making small cuts
: every 1/16 inch. How many cuts must be made to fringe
: the end?
: 答案:47(為什麼不是48呢?)
要切成48「段」只需要「切」47次(47 cuts)
: 2.第二題比大小更慘,我完全看不懂題意:
: A thin strip of binding 30 feet long just fits around
: the perimeter of a rectangular rug that covers an area
: of 54 square feet.
: A B
: The length of the
: longer side of the 10 feet
: rug
: 答案:B 比較大
: 謝謝大家
題意:30英呎長的鑲邊剛好可以鑲在面積54平方英呎的矩形地毯上
解:設矩形長 = x, 寬 = y
2(x+y) = 30
xy = 54
x+y = 15, y = 15-x
xy = x(15-x) = 54
x^2-15x+54 = 0
(x-6)(x-9) = 0
x = 9, 6
因設長 = x,故x = 9, y = 6
(以上內容由美加 黃冠文老師提供)
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