Any help how to do the problem?

Use Green's reciprocity theorem to solve the following two problems:[hint-for distribution 1,use the actual situation;for distribution 2,remove q,and set one of the conductors at potential V0]

(a)Both plates of a parallel plate capacitor are grounded and a point charge q is placed between them at a distance x from plate 1.The plate separation is d.Find the induced charge on each plate.[Ans.Q1=q((x/d)-1)]

(b)Two concentric spherical conducting shells radii a and b are grounded,and a point charge q is placed between them at distance r.Find the induced charge on each sphere.