[原始] 求GWD数学1、2、3几道题的解题思路

1-26：Running at their respective constant rates, machine X takes 2 days longer to produce w widgets than machine Y.  At these rates, if the two machines together produce 5/4 w widgets in 3 days, how many days would it take machine X alone to produce 2w widgets?


2-27：In a corporation, 50 percent of the male employees and 40 percent of the female employees are at least 35 years old.  If 42 percent of all the employees are at least 35 years old, what fraction of the employees in the corporation are females?

3-14：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)

我发现自己下的GWD30套好像跟讨论帖里面贴出来的不一样，所以找不到具体解题思路，望大家不吝帮助下~~~~~下个月7号第一次考，很紧张啊~~~
而且数学中这种百分比的题目我好想都比较晕~~~请问谁有比较清晰地对付这种题的思路呢？

谢谢谢谢谢谢谢谢大家！