一道sat数学题how many integers greater than 20 and less than 30 are each the product of exactly two different numbers,both of which are prime 答案是D=3 我算的是有21 22 23 29
2019-05-23
一道sat数学题
how many integers greater than 20 and less than 30 are each the product of exactly two different numbers,both of which are prime 答案是D=3 我算的是有21 22 23 29
优质解答
题目是:大于20小于30的整数中,有多少个是两个不同质数的积
答案是:21=3*7,22=2*11,26=2*13,一共3个
楼主理解题目错了吧?23和29我不知道你是怎么得到的
题目是:大于20小于30的整数中,有多少个是两个不同质数的积
答案是:21=3*7,22=2*11,26=2*13,一共3个
楼主理解题目错了吧?23和29我不知道你是怎么得到的