14. How many seconds will it take for a car that is traveling at a constant rate of 45 miles per hour to travel a distance of 22 yards?  (1 mile = 1,160 yards)

A.     8

B.     9

C.     10

D.     11

E.      12

我算了半天，怎么也对不上答案。我的思路是把45miles/hours转化成yards/second的形式，最后好像是14.5yard/sec。这样的话答案中就没有符合的了。不知道错在哪里？

18. Last year the price per share of Stock X increased by k percent and the earnings per share of Stock X increased by m percent, where k is greater than m.  By what percent did the ratio of price per share to earnings per share increase, in terms of k and m?

A.     k/m %

B.     (k-m) %

C.     [100(k-m)]/(100+k) %

D.     [100(k-m)]/(100+m) %

E.      [100(k-m)]/(100+k+m) %

正确答案是D。我能理解大致意思，但是不太清楚具体的思路，而且此题的最后一句读起来也很绕，请指点！