请教大学几道GMAT数学题哇~~

狮子珊

我想请教大家GWD第三套里面的几道数学题~ 谢谢亲们啦~~~
14.How many seconds will it take for a car that is traveling at a constant rate of 45miles per hour to travel  a distance of 22 yards?(1mile=1,160)
答案：C.10

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 incease,in terms of k and m?
答案：D.(100(k-m))/(100+m)%

A certain roller coaster has 3 cars,and a passenger is equally likely to ride in any 1 of the 3 cars each time that passenger rides the roller coaster.If a certain passenger is to ride the roller coaster 3 times,what is the probability that the passenger will ride in each of the 3 cars?
答案.C.2/9