please help with questions True or False

21. If two identical firms behave according to the Stackelberg model, the joint production is higher than if the same firms act as a Cournot.~ 22. The outcome of the Stackelberg model is a Nash equilibrium 23. A few firms with market power selling an identical product and competing over price arrive to the competitive equilibrium. ~ 24. In an oligopoly setting, joint profits are the highest when firms act according to a Stackelberg model. 25. In the presence of a negative externality generated by producing a good, a competitive market will produce less of that good than is socially optimal. ~ 26. An example of the tragedy of the commons is when farmers pump more groundwater from an aquifer than is socially optimal