问问大侠们一道GWD数学考题

yuchendawn

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

答案为什么是B  我认为是D

qujundi

i think D too.

charles1992

用文氏图很好解决，这题应该是选D，可能是GWD的答案错了吧~~