Question

In an examination, 70% examinees passed in Nepali, 55% examinees passed in English and 20% examinees failed in both subjects. If 90 students passed in both subjects, how many students appeared the exam?​

Answer 1

Step-by-step explanation:

If 10% failed both, then 90 % either passed only English or Only Maths or Both. ... No of students passed in english = 7* 100x /100 = 70x ... Out of 80 students in a class 20% were absent.

Answer 2

Answer:

200 students appeared in the exam

Step-by-step explanation:

Let the total number of student is x

Number of student passed in both subject is

n(A∪B) = n(A) + n(B) − n(A∩B)

Here,

n(A) = 70% of x

n(B) = 55% of x

Now, 20% failed in both subjects then 80% students passed in both the subjects right!!! (Think about it......)

n(A∩B) = 80% of x

∴n(A∪B) = (70x/100) + (55x/100) − (80x/100)

⇒(70x + 55x - 80x)/100

⇒ 45x/100 = 90

⇒x = (90 × 100)/45c

⇒x = 9000/45

∴x = 200

⇒ 200 students appeared in the exam

Hope it helped and you understood it........All the best