Answer should be A

3x/y is prime integer

let x = 15 y = 9

3*15/9 = 5

Here x is not equal to y

You can even take x = 21 and y = 9

vivek.kapoor83 wrote:If y ≠ 3 and 3x/y is a prime integer greater than 2, which of the following must be true?
Ⅰ. x = y
Ⅱ. y = 1
Ⅲ. x and y are prime integers.
(A) None
(B) Ⅰ only
(C) Ⅱonly
(D) Ⅲonly
(E) Ⅰand Ⅲ


I chose B. means if x=y , then expression would result in 3 always.So, I went for option B but OA is diff. I dont know where i am going wrong.

The question asks "which of the following MUST be true" - you showed that statement I COULD be true, which isn't the same thing.

3x/y = 5 or 7 or 11

Lets take 3x/y = 5

x/y = 5/3

x and y could take on many values one being 20/12

x=20 y=12

All 3 statements are false. Like Stuart said since its a must be question and we have dosproved all 3 choices


P.S For MUST be TRUE questions if u can disprove a choice with one set of values then that choice will not be part of the correct answer

For COULD be TRUEquestions if u can prove that a choice is true for one set of values then that choice will be part of the correct answer

Hope this helps also!
A)