Consider the following sequential bargaining game. Two players, A and B, have a total of $240,000 to divide between them. A makes an offer first, then B agrees or makes a counter offer and so on. Delay in reaching an agreement is very costly in that during the time between two offers the 'pot' shrinks by 50%. There are at most 4 rounds, i.e. if A rejects B's second offer, both players get zero.

(a) Draw the game tree.

(b) Find the subgame perfect equilibrium.