Question

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?

Answer 1

96 because 4 know all three and 100-4=96

Answer 2

2 because when you add up all the numbers the answer is 98 and 100-98 is 2