The given information is incomplete to make any calculations.
a) [Al3+(aq)] = 2.00 x 10⁻⁸ M, [OH-(aq)] = 6.00 x 10⁻⁸ M
b) [Al3+(aq)] = 4.00 x 10⁻⁹ M, [OH-(aq)] = 1.00 x 10⁻⁹ M
c) [Al3+(aq)] = 1.00 x 10⁻⁸ M, [OH-(aq)] = 2.00 x 10⁻⁸ M
d) [Al3+(aq)] = 8.00 x 10⁻⁹ M, [OH-(aq)] = 2.67 x 10⁻⁸ M