Statement:
Should there be a censor board for supervising advertisements issued by different companies?
Arguments:
I. No, It is impractical to have sensor boards for various purposes.
II. Yes, On many occasion it has been witnessed that an advertisement has created a lot of debate by showing such scenes in the advertisement as are detrimental to our social fabric.

Let us assume the two persons who can speak two languages speak Hindi and Tamil. The third person then speaks all the three languages.

Tamil ? Number of persons who can speak is 6. Only Tamil 6 ? 2 ? 1 = 3

Hindi - Number of persons who can speak is 15. Only Hindi 15 ? 2 ? 1 12

Gujarati ? Number of persons who can speak is 6. Only Gujarati 6 ? 1 = 5

Thus the number of persons who can speak only one language is 3 + 12 + 5 = 20

Number of persons who can speak two languages = 2

Number of person who an speak all the languages = 1

Total number of persons = 23.

No. of people who read Hindu = 285
No. of people who read TOI = 127
No. of people who read IE = 212
Now,
No. of people who read Hindu and TOI both is = 20
No. of people who read TOI and IE both is = 35
No. of people who read Hindu and IE both is = 29
Let No. of people who read Hindu , TOI and IE all is = x ;
So, only Hindu is = 285-20-29-x = 236-x ;
Only TOI is = 127-20-35-x = 72-x ;
Only IE is = 212-35-29-x = 148-x ;
Now, 236-x + 72-x + 148-x + 20 + 29 + 35 + x + 50 = 500 590 -2x = 500
So, x = 45 this is the value who read all the 3 dailies.
So, No. of people who read only one paper is = 236-45 + 72-45 + 148-45 = 191 + 27 + 103 = 321.

Given,

A + B = 2C ----(i)

C + D = 2A----(ii)

Adding (i) and (ii) we get : A + B + C + D = 2C + 2A  

=>  B + D = A + C

On interchanging - and /, we get the equation as

5 + 3 x 8 / 12 - 4 = 3

or 5 + 3 x (2/3) - 4 = 3

or 3 = 3, which is true.