Question

In a class, 70 students passed in Mathematics, 50% of the students passed in English,
25% of the students passed in both and 5% of the students passed in neither
Mathematics nor English.
How many students failed in atleast one subject
(a) 5
(b) 25
(c) 50
(d) 75​

Answer 1

Answer:

c) 50

Explanation:

Statement of the given problem,

In a class, 70% students passed in Mathematics, 60% passed in English, 1 student failed in both, and 16 students passed both. How many students are there?

Let N denote the total number of students in the class.

We know that

Number of students passed in Mathematics only = (70/100)*N - 16

Number of students passed in English only = (60/100)*N - 16

Hence from above data we get following relation,

N = [(70/100)*N - 16] + [(60/100)*N - 16] + 16 + 1

or N*(7/10 + 6/10 - 1) = 15

or N*(3/10) = 15 or N = 150/3 = 50 Answer