The resistance of a piece of wire is directly proportional to its length as the wire is cut in two equal parts

Resistance of each part = r/2

We know that in parallel combination equivalent resistance ; R = 1/R1 + 1/R2

So , Here R = 1/ r/2 +1/ r/2

= 2/r + 2/r

= 4/r

Thus, the resistance of the combination is 1/4th of the original resistance.