[求助]大全-4-17

One state adds a 7 percent sales tax to the price of most products purchased within its jurisdiction. This tax, therefore, if viewed as tax on income, has the reverse effect of the federal income tax: the lower the income, the higher the annual percentage rate at which the income is taxed.

The conclusion above would be properly drawn if which of the following were assumed as a premise?

(A) The amount of money citizens spend on products subject to the state tax tends to be equal across income levels.

(B) The federal income tax favors citizens with high incomes, whereas the state sales tax favors citizens with low incomes.

(C) Citizens with low annual incomes can afford to pay a relatively higher percentage of their incomes in state sales tax, since their federal income tax is relatively low.

(D) The lower a state’s sales tax, the more it will tend to redistribute income from the more affluent citizens to the rest of society.（A）

(E) Citizens who fail to earn federally taxable income are also exempt from the state sales tax.

请问这句话该怎么理解啊:

This tax, therefore, if viewed as tax on income, has the reverse effect of the federal income tax:

This sentence suggests that if you look at this tax as a tax on income (like income tax), it has the opposition effect of federal tax. Federal tax works in a way that the higher the income is, the higher the tax rate is. The sales tax is opposite: the lower the income, the higher the tax rate (because the 7% is on the goods purchased and steady).

對此題的assumption還是不清楚如何得出

我知道 poor: (income tas+ sales tax)/income   >   rich (income tax+ sales tax)/ income

但為何需要A這個前提?

另外 如何用"取非" 來驗證?

A说各收入段的人买东西（特指需要缴纳7%营业税的商品）花的钱一样多

==>缴纳的营业税一样多

又收入不一样

==>（营业税/收入）不一样，即the lower the income, the higher the annual percentage rate ...

A选项怎么理解呢？

为什么各个收入阶层在收税的商品上的花费必须趋于相等？不相等或者相差很大，题目中的结论也一样成立啊！

如果富人与穷人购买的此类商品数量2a与a，也就是在此类商品上的花费的比例是2，但他们的收入是3b与b，比是3，此时富人的花费比例是2a/3b，穷人是a/b,两个比例之比是2/3，这样的数字并不影响结论的成立（很明显，2a/3b要小于a/b）。

题中到底是怎样的一个推理？

Thanks for the explanation.

The lower the income, the higher the tax rate is..還是有点似懂非懂

是不是說: 穷人因為INCOME少 花得錢少 - 一各固定tax rate 7% is higher to them

所以前提就建立在INCOME少 -assumption - spend on prodcuts is less too.

oh, so that's why the answer is A,

請帮我鑑定思路对不对!!!

顶一下！请NN指点此类题该如何考虑？

但他们的收入是3b与b，比是3

如果假设他们的收入是2b与b呢，比是2，此时富人穷人的花费比均为a/b，可见前提是必需的，即假设他们在收税的商品上的花费必须趋于相等，才能得出题中的结论。