Powerbank Co. has established a business to supply large-capacity battery to EV manufacturers. It demand and supply functions are P^d = 20 - 0.05 Q^d P^s = 5 + 0.05 Q^s

^{a Calculate the profit-maximising price and output if PowerBank enjoys an effective monopoly in the market}

b Calculate the price and output if the competition makes the market become perfectly competitive

c Calculate the price and output if the supply continues to be competitive but Tesla becomes the only buyer of large-capacity car batteries in the market