A glass rod is rubbed against a silk cloth and an ebonite rod

A glass rod is rubbed against a silk cloth and an ebonite rod is rubbed against a piece of flannel. List the pairs which have
(a) similar
(b) dissimilar charges on them.
A.(a) Glass rod and flannel (similar charge i.e., positive); Silk and ebonite (both negative)
(b) Glass rod and ebonite rod.