Re: [CR. ] TN-13-Q4

看板GMAT (GMAT入學考試)作者Merica (美加文教)時間15年前 (2011/04/20 13:41)推噓0(0推 0噓 0→)

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一個現象是加稅，另一現象是香菸銷售下降。但是這兩現象之間不必然有因果關係。現在題目認定兩者之間是因果關係，那麼就必須補充必要條件。 D的意思是加稅前一包菸賣一塊錢，但是假若次年稅前價菸商主動先降到92cents，那麼加了8cents的稅不是又回到一塊錢？若是如此，那麼加稅就不是銷售下降的原因。所以D的意思是次年的稅前價(pre-tax price)不能少於92 cents，那麼一加稅，稅後價就超過一塊錢，比前一年貴了，所以銷售下降，兩者的因果關係就獲得確立。（以上內容由美加江璞老師提供） ※ 引述《dounts (忘記過去)》之銘言： : ※ 引述《cindy2015 ()》之銘言： : : Q. In the years following an eight-cent increase in the federal tax on a pack : : of cigarettes, sales of cigarettes fell ten percent. In contrast, in the : : year prior to the tax increase, sales had fallen one percent. : : The volume of cigarette sales is therefore strongly related to the : : after-tax price of a pack of cigarettes. : tax increase : P1 + T1 -----> P2 + T2 = P2 + T1 + 8 cent : ^^^^^^^^^^^^^^^^ : after-tax price : 結果得到 sales 下滑 1% : 題目歸因於 "after-tax price" : 意思就是 after-tax price ↑ --> sales ↓ : 問題是題目只說 tax incrase by 8 cents : assumption 橋段產生: : tax incrase by 8 cents --> after-tax price ↑ : P1 + T1 < P2 + T1 + 8 cent : P2 不能少於 P1 達到 8 cent 造成 after tax price 下滑 : after tax price 下滑就不能說 sales 下滑是此原因 : : The argument above requires which of the following assumptions? : : A. During the year following the tax increase, the pretax price of a pack of : : cigarettes did not increase by as much as it had during the year prior to : : the tax increase. : : B. The one percent fall in cigarette sales in the year prior to tax increases : : was due to a smaller tax increase. : : C. The pretax price of a pack of cigarettes gradually decreased throughout the : : year before and the year after the tax increase. : : D. For the year following the tax increase, the pretax price of a pack of : : cigarettes was not eight or more cents lower than it had been the previous : : year. : : E. As the after-tax price of a pack of cigarettes rises, the pretax price also : : rises. : : 答案是D : : 卻是看不明白怎麼推出的假設@@ : : 是根據什麼咧? : : 還請板友幫忙解答 : : 謝謝 -- ▅▅▅▅ ▅▅ ▅▅▅ ▅ ▅▅ ▅▅▅ █ █ █ █▅ █▄█ ▄ █ █▄█ █ █ █ █▄ █◥▅ █ █▅ █ █ -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 114.36.56.63