Question

In an examination of a certain class, at least 70% of the students failed in Physics, at least 72% failed in Chemistry, at least 80% failed in Mathematics and at least 85% failed in English. How many at lest must have failed in all the four subjects ?

Answer 1

I think 70% of students

Answer 2

Answer:

At lest 7% students failed in all the four subjects.

Step-by-step explanation:

Given :

Number of students failed in Physics = at least 70%

Number of students failed in Chemistry = at least 72%

Number of students failed in Maths = at least 80%

Number of students failed in English = at least 85%

To find : How many at lest must have failed in all the four subjects ?

Solution :

We can also say that the given condition could be,

Number of students passed in Physics = at most 30%

Number of students passed in Chemistry = at most 28%

Number of students passed in Maths = at most 20%

Number of students passed in English = at most 15%

Therefore, Total number of students passed in all subjects  is

Atmost ( 30+28+20+15) % = 93%

So,Total number of students failed in all the subjects is

Atleast (100 - 93)% = 7%