腦力激盪的時間到了... (血糖太低勿入)

捷運出題國小數學難解 連碩畢生都被考倒<br /> <br /> 附原新聞連結http://www.ettoday.net/news/20120910/100468.htm?from=fb_et_news<br /> <br /> <br /> <a _alt="" href="http://forum.fashionguide.com.tw/upload_image/forum/1/6/3/2/201209101746520.jpg" id="http://forum.fashionguide.com.tw/upload_image/forum/1/6/3/2/201209101746520.jpg?post_id=13094493" name="linkImg" target="_blank" onclick="return LoadImg(this.id);"><img border="0" alt="" src="http://forum.fashionguide.com.tw/i/showThePic.jpg" onload="java:if(this.width>500) this.width=500;"></a><br /> <br /> <span style="font-size: medium; ">答案是ㄅ=2</span><br /> <span style="font-size: medium; "><br /> 解法：</span><br /> <br /> <span style="font-size: medium; ">a+b+c+d+e+f+g+h+i-ㄅ<span style="color: rgb(255, 0, 0); ">+2ㄅ</span> = 2012<span style="color: rgb(255, 0, 0); ">+2ㄅ<br /> </span>a+b+c+d+e+f+g+h+i+ㄅ = 2012+2ㄅ<br /> 45 = 2012+2ㄅ<br /> <br /> 左右同取mod 9 <br /> 0 = 5 + {(2ㄅ)取mod9} <span style="color: rgb(0, 0, 255); "> (45/9餘數=0 ; 2012/9餘數=5)</span><br /> (2ㄅ)取mod9 = -5<br /> (2ㄅ)取mod9 = 4   <span style="color: rgb(0, 0, 255); ">(2ㄅ mod9=(2ㄅ+9)mod9)</span><br /> <br /> 故2ㄅ = 4 or 13 or 22 ..... <br /> <br /> >>><u>ㄅ = 2 or 6.5 or 11....(只有2合)</u></span><span style="font-size: large; "><br /> <br /> <span style="font-size: medium; ">應該是這樣沒錯...</span><br /> -------------------------------------------------------------------<br /> <br /> <br /> <span style="font-size: medium; ">結論：<br /> 浪費我30分鐘，害我現在肚子很餓...<br /> 我國小連mod是什麼都不知道...<br /> </span><span style="font-size: medium; ">分明就是補習班招生要騙家長的花招!!</span><br /> </span><br /> <br /> <br type="_moz" /> <br />