(1) Consider a pair of quarks with colours R and B and a third quark G. Establish whether the force of the pair on G is attractive or repulsive for each of the combinations RB + BR and RB - BR. Considering quarks of the same colour, establish which of the following processes are allowed or forbidden, giving the reasons: 

(2)W⁺ → b̅_L + c_R and 

(3) Z → τ⁺_R+ τ^- _R .