Samsung Electronics has ordinary shares amounting to ₩1,200,000,000 and 10% debentures of ₩300,000,000. Sony Corporation has ordinary shares worth ¥800,000,000 and 12% debentures of ¥200,000,000. Volkswagen Group's capital structure includes €700,000,000 in ordinary shares and €400,000,000 in 15% debentures.
In 2017, the return on capital employed for each firm was 20%, and in 2018 it was 10%. The corporation tax rate in both years was 50%, and debenture interest is deductible for tax purposes.
(a) Determine the percentage return on the shareholders' capital for each company for 2017 and 2018. Assume all profits are distributed. 

(b) Evaluate the pros and cons of high financial leverage for these companies.