CFG

I need help with d, e, and f.

Design a CFG for each of the following languages: a) L_1 = {a^ib^jc^k | (i notequalto j), where i, j, k greaterthanorequalto 0} b) L_2 = {a^ib^jc^k | (i notequalto k), where i, j, k greaterthanorequalto 0} c) L_3 = {a^ib^jc^k | (i notequalto j or i notequalto k), where i, j, k greaterthanorequalto 0} d) The set of all strings over alphabet {a, b} such that the number of a's is at least as many as the number of b's. e) The set of all strings over alphabet {a, b} that are of odd length. f) The set of all strings of a's and b's that are not of the form ww^R