蓝书上163页199、201题

chongov

199. If k and w are the dimensions of a rectangle that has the area 42, and if k and w are integers such that k>w, what is the total number of possible values of k?
正确答案（C）4
我的答案（E）6
按照题意，kw/2=42, kw=84=2*2*3*7，
应该有6种可能：
k=12, w=7
k=14, w=6
k=21, w=4
k=28, w=3
k=42, w=2
k=84, w=1

201. Last year the annual premium on a certain hospitalization insurance policy was $408, and the policy paid 80 percent of any hospital insurance policy last year was equal to the annual premium plus the amount of hospital expenses not paid by the policy. What was the total amount of hospital expenses last year?
正确答案：$680
这题让我彻底SB了，看了半天不知道题意

Simon88

第一题KW=42，不用除以2吧，这样就是7、14、21、42四个

Simon88

第二题应该是0.2x+408=0.8x吧。。。。

大红大紫

楼上正解

第二个的确有点乱

chongov

为何kw不用除以2？kw不是直角三角形的两条边吗？

大红大紫

那个是矩形啊...

chongov

看错题目了，囧，谢谢啊