请教几道数学问题，情写明思路，谢谢！！！！！！！！！！
1.What is the value of n?
(1) n(n –1)(n – 2 ) = 0
(2) n2 + n – 6 = 0

答案是C（但我觉得应该是E）

1. At a certain picnic, each of the guests was served either a single scoop or a double scoop of ice cream. How many of the guests were served a double scoop of ice cream?
(1) At the picnic, 60 percent of the guests were served a double scoop of ice cream.
(2) A total of 120 scoops of ice cream were served to all the guests at the picnic.

答案是C（我觉得是E）

if n is an integer, then n is divisible by how many positive integers?
(1) n is the product of two different prime numbers.
(2) n and 23are each divisible by the same number of positive integers.

答案是D

第一条题目，　　　如果n(n-1)(n-2) =0     n = o  or 1 or 2.   
                                            n2+n-6=0        n=-3 or 2 .      
                                      两个取交集，　n=2        xuan  c  .

第二条题目，　假设宾客人树为Ａ．　根据条件一和二．　0.6a*2 +0.4a*1=120 .  那总的宾客树就出来了．　那其中的０．６　也就出来了

第三条　　（１）　Ｎ　是两个质数的积，　　那这两个质数就是他的因子，　　而且１不是质数哦
　　　　　　（２）　Ｎ　和２３被同样数量的整数除，　　２３的因子为　１　和２３．　所以Ｎ也就两个．　　

If n is an integer, then n is divisible by how many positive integers?
(1) n is the product of two different prime numbers.
(2) n and 23 are each divisible by the same number of positive integers.

(1) Suppose n = pq, where p and q are different primes.  As neither prime have any nontrivial factors, the factors of n are 1, p, q, and pq = n.  So there are four positive integers that are factors of n.

(2) 23 is a prime number, so it has exactly two factors.  That means n also has 2 factors.

Therefore, D is the correct answer.

One thing unusual about this question:  The answers obtained by (1) and (2) are not the same.  Normally for the GMAT, the answers are the same.  I wonder whether there is a typographical error in (2).