The equation of the given lines are
3x+y−2=0...(1)
px+2y−3=0....(2)
2x−y−3=0....(3)
On solving equation (1) and (3) we obtain
x=1 and y=−1.
Since these three lines may intersect at one point, the point of intersection of lines(1) and (3) will also satisfy lines(2)
p(1)+2(−1)−3=0
p−2−3=0⇒p=5.