[計量] GWD-13-35

看板GMAT (GMAT入學考試)作者 (歆小喵)時間16年前 (2009/07/23 23:11), 編輯推噓1(104)
留言5則, 1人參與, 最新討論串1/1
Stations X and Y are connected by two separate, straight, parallel rail lines that are 250 miles long. Train P and train Q simultaneously left Station X and Station Y, respectively, and each train traveled to the other’s point of departure. The two trains passed each other after traveling for 2 hours. When the two trains passed, which train was nearer to its destination? (1)At the time when the two trains passed, train P had averaged a speed of 70 miles per hour. (2)Train Q averaged a speed of 55 miles per hour for the entire trip. ans:原為C,但是在傷咖裡的討論串有人說是a? 討論串中說A理由充分的原因是因為選項說"在交會時的平均速率為70", 所以代表p已經走了140miles了 可是我的疑問是:在交會時的平均速率=前兩小時的平均速率嗎? 如果是在交會前兩秒加速的怎麼辦? (完了我覺得這好像跟我的理化程度有關) -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 61.228.72.4

07/25 00:40, , 1F
我覺得是A吧 翻交會時的平均速率不太準確 應該說"兩台火車
07/25 00:40, 1F

07/25 00:41, , 2F
交會時 火車P的平均速率是一小時70 mi" 平均速率應該是指從
07/25 00:41, 2F

07/25 00:41, , 3F
發車交會時的平均速度 即使是交會前兩秒加速到150 題目既給
07/25 00:41, 3F

07/25 00:42, , 4F
定交會時平均速率是70 可見他之前可能速度都低於70 應該是
07/25 00:42, 4F

07/25 00:42, , 5F
這樣吧?! :D
07/25 00:42, 5F
文章代碼(AID): #1AQ7sbmP (GMAT)
文章代碼(AID): #1AQ7sbmP (GMAT)