Question

In an examination 50% of students passed in mathematics and 70 % of students passed in science while 10% students failed in both subjects. 300 students passed in atleast one subject. Find the total number of students appeared in the examination if they took examination in only two subjects.

Answer 1

Let total no. of people= x
50% passed in mathematics=50x
70% passed in science= 70x
10% failed= 10x
Therefore- 50x+10x+70x=x
3x-x= 50+70+10
2x= 120+10
2x= 130
x= 130/2= 150
Total no. of people passed in at least 1 subject= 300
so, total no. of people= 150+300= 450 students.