GWD第三套数学题

亲们~~~想请教大家几道GWD第三套里面的几道数学题~~谢谢你们~！

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=1,160yards)
答案：C.10

16.If n is positive integer and r is the remainder when (n-1)(n+1) is divided by 24,what is the value of r?
(1).2 is not a factor of n
(2).3 is not a factor of n
答案：C

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?
答案 D.(100(k-m))/(100+m)%

另外还有一题，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

谢谢你们~！