A survey of 100 students was taken concerning their knowledge of foreign languages. The results were as follows:
30 know French
19 know German
16 know Russian
11 know both French and Russian
12 know both French and German
6 know both German and Russian
4 know all three languages
How many students do NOT know any of the three languages?
30 know French
19 know German
16 know Russian
11 know both French and Russian
12 know both French and German
6 know both German and Russian
4 know all three languages
How many students do NOT know any of the three languages?