1.Which of the following procedures is always equivalent to adding 5 given nembers and then dividing the sum by 5?
(1)Multiplying the 5 numbers and then finding the 5th root of the product.
(2)Adding the 5 numbers, doubling the sum, and then moving the decimal point one place to the left.
(3).Odering the 5 numbers numerically and then selecting the middle number.
答案：（2）正确
我的答案是相反的，所以恳请NN们解释一下提干，谢谢！
2.If positive integer x is a multiple of 6 and positive integer y is a multiple of 14, is xy a multiple of 105?
(1) x is a multiple of 9
(2)y is a multiple of 25.
答案:B 请指教
3.Seven different numbers are selected from the integers 1 to 100. and each number is divided by 7. What
is the sum of the remainders?
(1) the range of the seven remainders is 6
(2)The seven numbers selected are consecutive integers.
答案：B
A是怎么排除的？ 我试了好多情况，好像（1）和（2）是一回事？
4.If x,y,p,and q are positive, is x>=y?
(1) px/qy=p/q
(2) xy=p
答案：A 我的疑问是：（1）得出x=y,可是这并不能判断出x>=y呀？
题目有点多，希望大家捧场
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