A company with seven 51% subsidiaries has taxable total profits of £ 140,000 for the year to 31 March 2018. Dividends received in the year were £50,000. Calculate the corporation tax liability for the year and state the date (or dates) on which this tax i s due to be paid, assuming that the company was "large" in the year to 31 March 2017 and either:

(a) all of the dividends received were intra-group dividends, or

(b) none of the dividends received were intra-group dividends.