这题是进入数学的第一题!! 1. in a 1-mile distance, P finished it in R miles per hours, if the time he used was R+20 per hour, he would have used 4 minutes less than the original, what is R? a. 5 b. 10 c. 20 d. E. 忘了。 这题感觉很简单 偏偏我那时候脑袋就当了。。。想了3分钟还是想不起来。。就随便点了答案 C.....
2. If m and r are two postive integers, the sum of the tens digit of m and r is 14, what is the largest possbile value of mr? 求m和r 的 乘积。。 3. [attachimg=178,171]74078[/attachimg](正方形哦 我画的不太正而已 呵呵 30是30° 在画图上找不到° , 中间也是正方形 但是比我画的小多了。
求 ratio of the area of the triagles and the quadrilateral (里面的那个)