----------------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 180 students answered yes only for subject M, how many of the students did not answer yes for either subject?
Choose the correct choice from the following answers.
A) 100	B) 220	C) 300	D) 400	E) 500
Since 180 students answered yes only for subject M, then the remaining 320 students who answered yes for subject M, also answered yes for subject R. So, 320 students answered yes for both subjects.   If 320 students answered yes for both subjects, then 400-320= 
<gadget id="calculator">400-320</gadget>
<output>80</output>
80 students answered yes only for subject R.   So, we have that:   200 students answered yes only for subject M;   80 students answered yes only for subject R;   300 students answered yes for both subjects;   Therefore 800-(200+80+300)= 
<gadget id="calculator">800-(200+80+300)</gadget>
<output>220</output>
220 students did not answer yes for either subject.   Answer: 220.
<result>B</result>
----------------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 180 students answered yes only for subject M, how many of the students did not answer yes for either subject?