Question

In an examination, 80% of the students passed in English, 85% in Mathematics and 75% in both English and Mathematics. If 40 students failed in both the subjects, find the total number of students.

Answer 1

heya !

let n(A) = no. of students pass in english

n(B) = no. of students pass in math

n(C) = no. of students pass in either math or english

n(D) = no.of students pass in both math and english

let x are no. of students

n(C) = n(A) + n(B) - n(D)

= 80x/100 + 85x/100 - 75x/100

= 90x/100

no. of students fail in both either math or english = x - n(D)

40 = x - 90x/100

40 = x/10

x = 400

total no. of students = 400

Answer 2

Answer:

Given :

80% passed in English and 85% passed in Mathematics and 75% in both the subjects

Solution :

• then total passed students

=85+80-75

=90%

•so failed students

=10%=40

•so total students

=100×40÷10

=400