posted by Anonymous .
90% of all students passed in Hindi, 85% in Maths and 150 students passed in both. calculate total number of students in the school.
N( A or B) = N(A) + N(B) - N(A and B)
let the number of students be x
100% x = 90%x + 85% x - 150
x = .9x + .85x - 150
- .75x = -150
x = 200
There are 200 students in the school