Neco Model Questions Vol1 2018 Civic Education Question 22

A community evaluates three conflict‑resolution mechanisms - Mediation, Arbitration and Community Court - on three criteria: Speed (weight 0.4), Fairness (weight 0.35) and Cost‑efficiency (weight 0.25). The scores (out of 100) are:\n\nMediation: Speed 78, Fairness 85, Cost 90;\nArbitration: Speed 85, Fairness 80, Cost 70;\nCommunity Court: Speed 70, Fairness 90, Cost 60.\n\nThe overall effectiveness of a mechanism is the weighted sum of its three scores. Because of budget limits the community can adopt only two mechanisms, and the combined overall effectiveness (average of the two mechanisms' scores) must be at least 80. Which pair(s) of mechanisms satisfy this condition and what is the combined effectiveness score for each qualifying pair?