真是太弱了，两个题目有点CONFUSED ，

Q33:。。。？ A salesperson received a 6-percent commission on the amount of total sales up to and including $10,000, and an r-percent commission on the amount of total sales over $10,000. If the salesperson received a total commission of $920 on total sales of $14,000, what was the value of r?

A. 3.2

B. 4.3

C. 6.6

D. 8.0

E.9.2

我怎么就算得约是6.6呀，因为14000超过10000，所以直接r%*14000=920 r约=6.6，这样条件A salesperson received a 6-percent commission on the amount of total sales up to and including $10,000,都用不着拉，偶非常弱，不明白的说，ZAZA，是不是理解上出了事？

与以下的比较

Q37: 注意

A certain state has a sales tax of 5 percent on the portion of a purchase price that is greater than $100. If a customer paid a sales tax of $4 on a particular item, what was the purchase price of the item?

A. $120

B. $124

C. $180

D. $184

E.$220 这里不就是5%乘以purchase price=4 purchase price=80，咦小于100的？这时偶就蒙的就是180，因为前面有100。但是根据公式不就是这样算吗？那里出问题？怎么是180？不知道，我不知道！！

这两个题目有很大的相识的地方，估计我肯定哪里没想到什么，哎，糊涂啊不知道哩。。。。。。。。

Your understanding is wrong.

Q33

The portion <=10,000, pay 6% commission The portion >10,000, pay r% 10,000*6% + (14000-10,000)*r% = 920

Q37

5% is charged only for the portion >$100. If the portion <= $100, no

tax is charged. $4/0.05 + 100=180