[原创]8月数学机经全总结（讨论稿，8.23，198题）

atongmu

179. (1-1/5)/(1+1/5)=?
参考答案：2/3
思路：

atongmu

183. car a can go 25 miles/gallon of gasoline, while car b can go 11.9 miles/gallon of gasoline. if both cars are driven 12,000 miles, how many more gallons of gasoline will car b consume than will car a? (rounded to the unit digit)
参考答案：528.40
思路：
这道题可能有陷阱，我12代替11.9算得出520——一个很有诱惑力的答案。

atongmu

184. a company increases its costs/labor charges from $50/hour to $60/hour and enhances its parts charges by 8%. a certain job requires 1.5 hours of labor charges and parts charges, and the parts charges before change were $125/hour. what percent will the total charges for this job increase?
参考答案：1/8
思路：

atongmu

185. among the 600 attendees of a conference, 250 are republicans and 100 vegetarians. how many of the republicans are vegetarians?
1) 300 are neither republicans nor vegetarians
2) 200 republicans are not vegetarians
参考答案：B
思路：
最近很多题目都是这种思路，换汤不换药。

atongmu

186. the average salary for company a is $3500, and the average salary for company b is $4500. how many people are in company a?
1) the average salary for company a and company b is $4200
2) there are totally 500 employees in a and b.
参考答案：C
思路：

atongmu

187. ax+by+c=0. the slope is 1/2. what’s the value of b?
1) a=2;
2) c=4
参考答案：A
思路：-a/b=1/2

atongmu

188. 30!/10! is expressed as the product of integers. the biggest integer is 30. what’s the smallest integer?
参考答案：11
思路：

atongmu

189. there are 500 marbles in a jar. 200 are red, 100 are blue, and 200 are green. if two marbles, one at a time without placements, are taken from the jar. What’s the possibility that both marbles are red?
参考答案：C200,2/C500,2
思路：

atongmu

190. 123456789的平方，unit is the X, tenth is the Y, ask X=? Y=?
参考答案：尾数为21
思路：只要乘最后2位

atongmu

193. 一人，　工资由３２，０００增加到３３，０００。问增长比例。
参考答案：3.125%
思路：

[此贴子已经被作者于2003-8-23 16:41:34编辑过]