Confusing equation - Set11 Q5

[arocks]

If (y+3)(y-1)-(y-2)(y-1)=r(y-1), what is the value of y?
1) r^2=25
2) r=5

I do not understand why we need to find y at all....Here's my approach...

(y+3)(y-1)-(y-2)(y-1)=r(y-1)
or (y-1)[(y+3)-(y-2)]=r(y-1)
or [(y+3)-(y-2)]=r
or y+3-y+2=r
or 5=r

So ultimately, there is no y. So both the statements are irrelevant.
But can we have a DS question where we do not need to find/prove anything? I may have missed something here, i didn't get the point of this question.

Please explain. Thanks.


OA is E [spoiler][/spoiler]

[samirpandeyit62]

Hey arocks,
The Q asks "what is the value of y?", and that is what we need to find here, though we can find r without using y.

now

(y+3)(y-1)-(y-2)(y-1)=r(y-1)

stmt 1 :

r^2 =25 so r =-5 or 5

in both cases i.e plugging r=5 or -5 we will end up with a quadratic eqn with y raised to power of 2, hence it will have atleast two solns the two values of r

not suff

stmt 2 :

r =5

again the same case, if we plug in the value of 5 we will get a quadratic eqn of y so it will have two roots so INSUFF

combine: same as stmt 2

so E

[arocks]

Hey thanks....makes sense...but it was a 'different type' of question nevertheless!