gwd15-33前提问题！

Economics

Q33:

Of the families in City X in 1994, 40 percent owned a personal computer.  The number of families in City X owning a computer in 1998 was 30 percent greater than it was in 1994, and the total number of families in City X was 4 percent greater in 1998 than it was in 1994.  What percent of the families in City X owned a personal computer in 1998 ?

 A.     50%

 A.     50%

B.     52%

C.     56%

D.     70%

E.      74%

这道题我是做“对”了，答案是A。但是我的做法是：假设The number of families in City X in 1994=XSo，percent of the families in City X owned a personal computer in 1998 =X*0.4*1.3/（X*1.04）=0.5

这种做法有个前提：One family owns one PC.这在题目中并没有交代。我个人没看出如果不设置前提的话可以怎么做，请大NN看看！

Economics

LZ没看明白我的意思，可能我说得不够清楚，但是也不要紧了，我发现是自己钻死脑筋了。

oldersea

文中并没有这个前提，你在看看题干呢，是说X这个城市里面40%的家庭有一台计算机，（这里就说明不可能每一家都有一台计算机呢）98年有一台计算机家庭的数量比94年上升了30%.后面依次类推。X*0.4*1.3/（X*1.04）=0.5这个算式是对的。