一道sat2数学题,
问题描述：
一道sat2数学题,
the only prime factors of a number 'n' are 2,5,7,and 17.which of the following could not be a factor of
a）10 b) 20 c) 25 d)30 e)34
答
亲,选择C吧,题目意思是说,只能n的因子只能是2,5,7,17,而10=2*5,20=2*2*5,30=2*3*5【3不符合要求】,34=2*17,所以选择C.