Data Sufficiency (DS) | Re: In the x-y plane, region S is defined by x ≤ 0, y ≥ 0 and 3y -5x ≤ 15.

A) a*b=-4
x is -ve; y is +ve.
consider all possibilities for a and b
1* -4; -1*4 and 2*-2. For all the numbers 3y-5x is always > 15. So answer is no. Suffecient.

B) b-a=5
Consider b=4 and a=-1 (like in A) 3y-5x=17 .Answer is no.
However if we consider b=5 a=0, then 3y-5x=15. Answer is yes.
B is not suffecient. A is the answer

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