几道Prep数学求助！！

Rheinweg

1.List k consist of 12 consecutive integers.If -4 is the least integer in list k,what is the range of the posistion integers in list k?
5
6
7
11
12
选6 我不明白这个range是什么意思？？


2.Alice's take-home pay last year was the same each month ,and she saved the same fraction of her take-home pay each month.The total amount of  money she saved at the end of the year was 3 times the amount of that portion of her monthly take-home pay that she did not save.If all the money that she save from her take home pay,what fraction of her take-home pay did she save each month?

1/5 求思路？？

Last month 15 homes were sold in Town X.The average sale price of the homes was 150,000 and the median price is 130,000,what the following statement must be true?

i.at least one of the homes was sold for more than165,000
ii.at least one of the homes was sold more than 150,000
iii.at least one of the homes was sold less than 130,000
选i,完全莫有思路！！！

坚定之路

rang简而言之就是这个数列中最大值减最小值；
如果那个人每月储蓄收入的1/5，那么12个月后，她的总储蓄是月收入的12/5，因为她每月的消费是月收入的4/5；因此她年储蓄额是月消费额的3倍；此题列个方程即可求解；
第3题有点怪，我觉得i和ii都对；由于中位数是130,000，所以起码有8个房子被以不高于130,000的金额售卖，为了使平均数达到150,000，对应每个以不高于130,000被卖掉的房子，必有一个以不低于170,000被卖掉的房子对应，这样i和ii都成立；iii不正确，因为可能的情况是有8个房子被以130,000的金额卖掉，而剩下7个房子则以高于130,000的金额被卖掉。