Given,
S1≡x2+y2−10x+4y+13=0 with radius R=4 and its one diameter is chord of other circle S2 whose centre is given by intersection of 2x+3y=12&3x-2y=5 which is (3,2)
Now, plotting the diagram we get,

Now, from above circle the distance between the centres is given by l=(5−3)2+(−2−2)2=20
Hence, radius of S2 will be, r2=(20)2+42=20+16=36
⇒r=6