请教数学题目

tangyunjie

last year in a group of 30 businesses , 21 reported  a net profit and 15 had investments in foreign markets. How many of the businesses did not report a net profit  nor invest  in foreign markets last year?

1   last year 12 of the 30 businesses reported a net profit and had investments in foreign  markets .
2   last year 24 of the 30 businesses reported a net profit or invested in foreign markets , or both

答案是B，个人感觉第一个条件也绝对没问题，所以是D，不知道大家怎么想？

nwy1980

我也做过这题。。GWD的
认为答案错了 1可以算的出来~~~~和2是一样的