Question

In an examination 50% of the students passed in Maths 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 subjects.

Answer 1

As 10% failed in both subjects
So 90% students passed in at least one exam
90/100*x=300
x=333.33
But it's coming in fraction so I am not sure

Answer 2

Given that 50% passed in maths that implied that 50% failed in maths. Also, 70 % passed in science mean that 30% failed. Therefore, total % failed in atleast one of the subjects is 50+30-10 = 70%. This implies that 30% of the students have passed in atleast one of the subjects and that is given as 300. Hence, 30% is 300 means that 100% is 1000.