nobelgirl777 wrote:
----------------YES---------NO----UNSURE
Subject M----500--------200-----100
Subject R----400--------100-----300
A total of 800 students were asked whether they found two subjects, M and R, interesting. Each answer was either "yes" or "no" or "unsure", and the numbers of students who gave these answers are listed in the table above. If 200 students answered "yes" only for subject M, how many of the students did not answer "yes" for either subject?
A. 100
B. 200
C. 300
D. 400
E. 500
Since 200 students answered "yes" only for subject M,
then the remaining 300 students who answered "yes" for subject M, also answered "yes" for subject R. So, 300 students answered "yes" for both subjects.
If 300 students answered "yes" for both subjects, then 400-300=100 students answered "yes" only for subject R.
So, we have that:
200 students answered "yes" only for subject M;
100 students answered "yes" only for subject R;
300 students answered "yes" for both subjects;
Therefore 800-(200+100+300)=200 students did not answer "yes" for either subject.
Answer: B.
Hope it's clear.
how did you deduce that the remaining 300 students must have said Yes to Subject R. There can be students who might have said Yes to Subject M and No to R and still be counted towards 500 who said Yes to M. Am I reading the premise wrongly?