Re: [計量] 幾題計量問題??

看板GRE (GRE入學考試)作者EdwardLin (起司蛋糕形的我的愛情)時間16年前 (2010/04/05 21:52)推噓0(0推 0噓 0→)

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※ 引述《tako1016 (Tako)》之銘言： : 不好意思 : 又要請各位幫忙了 : 1.A merchant purchased a jacket for $60 and then determined a selling price : that equaled the purchase price of the jacket plus a markup that was 25 percent : of the selling price.During a sale, the merchant discounted the selling price : by 20 percent and sold the jacket. What was the merchant's gross profit on : this sale ? : Ans:$4. 設selling price = x, 則 x=60+0.25x --> x=80 new selling price = 80*0.8=64 gross profit=64-60=4 : 2. A circle passes through the three vertices of an isosceles triangle that : has two sides of length # and a base of length 2. What is the area of this : circle? : Ans: 81/32 pi 請自行想像圖形設等腰三角形頂角為A, 底邊兩頂點為B and C外接圓心為O, AO延長交BC於H OA=OB=OC=半徑=r AB=AC=3, BH=1 --> AH=2根號2 --> OH=AH-OA=2根號2-r 則直角三角形OBH中, OB^2=OH^2+BH^2 --> r^2=(2根號2-r)^2+1 解方程式可得r^2=81/32 : 3. In the rectangular coordinate system, if a line passes through the : points (-10, -18), (20,22) and (x,2), then what is the value of X? : Ans: 19 任兩點連線斜率相同 [22-(-18)]/[20-(-10)]=4/3=(22-2)/(20-x) --> x=5 : 6. This morning Pat want to the market with a red bag and a green one. If he : bought 10 carrots and 6 radished, in how many ways could he distrbute these : vegetables so that no bag would be empty? : Ans:75 只考慮red bag, 因為沒放在red bag的就會放在green bag 可以放0~10個carrot和0~6個radished, 共11*7=77種可能扣除兩個都是0和兩個都放滿的兩種可能, 共75種可能 : 7.A cylindrical tank with radius 4 feet and height 9 feet is lying on its side. : The tank is filled wiht water to s depth of 2 feet. What is the volume of the : water, in cubic feet? : Ans:48pi-36根號3 嗯... 畫圖就可以解了, 簡單說就是要求一個弓形的面積 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 111.248.11.34