Construct a Pushdown Automata (PDA) for the following language:

1 L = {w ? {a, b}* | (w = w^R) and number of a's = number of b's}

2 L = {a^i b^j c^k | i?j or j?k}

3 L = {w ? {a, b}* | number of a's < number of b's}