0In an examination 50% of the students passed in Mathematics and 70% of students passed in Science while 10% students failed in both subjects. 300 students passed in
at least one subject. Find the total number of students who appeared in the examination,
if they took examination in only two subject?
Solution:
Given
Passed percentage in M=50%, S=70%,
300 students passed in atleast one subject.
10% failed in both subject.
so remaining 90% passed atleast in one subject.
n(M∪S)=n(M)+n(S)-n(M∩S)
90%=50%+70%-n(M∩S)
n(M∩S)=30%
so, 30% of X=300
X=1000.
The total number of students is 1000.
