Re: [問題]請問來欣的數學問題 M8 :)

看板GRE (GRE入學考試)作者officium (officium)時間17年前 (2007/06/03 16:43)推噓2(2推 0噓 1→)

留言3則, 2人參與討論串3/3 (看更多)

太謝謝你了不過我搞不太懂第17 我老是弄不清楚那個those 哪個時候指原本的全部人哪個時候指某依部分的人呢我以前都是看those跟在誰後面就是指誰可是為什麼這題是指全部人 ※ 引述《tingting88 (啊哈哈哈哈哈哈哈)》之銘言： : ※ 引述《officium (officium)》之銘言： : : M8 : : 17 : : In a nationwide poll, N people were interviewed. : : If 1/4 of them answered ”Yes” to Q1, : : and of those, 1/3 answered “Yes” to Q2, : : which of the following expressions : : represents the number of people interviewed who : : did not answer “Yes” to both Q? : 他的意思應該是1/4的人在Q1回答yes,然後這些人當中又有1/3的人在Q2回答yes : 最後他問有多少人沒有兩題都回答yes,所以答案應該是 N*(1-(1/4)*(1/3))=11N/12 : : 30 : : The organizers of a fair projected a 25% increase in : : attendance this year over : : that of last year, but attendance this year actually decrease by 20%. : : What percent of the projected attendance was the actual attendance? : 假設去年的出席率是x 假設的是1.25x 實際的是0.8x : 他問的是 0.8x/1.25x=64% (其實我也看不太懂題目,是照答案推的=.=) : : 22 : : A hiker walked for 2 days, On the second day the hiker walked : : 2 hours longer and at an average speed 1 mile per hour faster : : than he walked on the first day. IF during the two days he walked : : a total of 64 miles and spent a total of 18 hrs walking, what : : was his average speed on the first day : : 我設第一天走 x小時所以第二天 x+2 : : 2x+2=18 x=8 : 到這邊沒問題接著假設第一天的平均速率是v 所以第二天的是v+1 : v*8+(v+1)*10=18v+10=64 v=3 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 59.117.100.93