GMAT机经：2017年8月数学（至8.17）（十七）.

　　8.4——8.17 从126题更新至353题

　　8.13

　　316 给了26个字母排出顺序m在中间吧，说什么是在书里出现的频率由高到低排列，没有一样的情况，书有超过3000页，问随机抽取一个字母是m的概率会不会大于1/26?选B吧

　　1)抽到某个字母姑且当是x吧记不清了的概率是1/25，这个字母在m前面

　　2)抽到l的概率是1/25，这个字母在m后面

　　317 store purchase n clocks with a total cost of t and sell them for d per clock. If the store need to buy 100 more clocks with the cost per clock unchanged and also sell them for d per clock, what is the profit the store made from the additional 100 clocks?

　　A.100d-100t/n B. 100d/n-100t C 100(d-t) D.100d-t E. d-100t 我选A

　　318 是说工资是每小时给多少钱，然后搬运一件东西好像在给多少钱~

　　james is payed $7.5 per hour and $ 1.5 perDILIVERY 之类的 in the first 8 hours, and is payed $9 per hour and $3 per unit in the following hours。 if he works for 10 hours and 25 unit, in which 7 units are finished in the last two hours, what is his pay?

　　这里UNIT是指搬运几件东西!

　　8*7.5+18*1.5+2*9+7*3=126比较确定!!!

　　319 The concil has 9 male members and 7 female members, if a meeting must select at least one male member and one female member, how many permutations are possible?

　　A. 81 B.221 C.441 D. 不记得了 E882 选C

　　320 The meeting must supply 420 cups of coffee.both the cups and pots are cylinder.A cup is with a diameter of 7 and a height of ***(不记得了) inner side，and a coffee pot is with a diameter of 18. what is the height of the pot?

　　I. one pot could fill in 30 cups.

　　II. the meeting need 14 pots.

　　我选D

　　321 Rectangular floor in a certain room has a area of 108 and perimeter of 42, 求dimension of the floor

　　322 说n是一个两位正整数 问N是否小于30

　　1. n的个位数比10位数大7

　　2 n是个位数和十位数数字之和的2倍