1. Capital Employed:
\[
\text{Capital Employed} = \text{Total Assets} - \text{Current Liabilities} = ₹ 22,00,000 - ₹ 2,00,000 = ₹ 20,00,000.
\]
2. Net Profit Before Tax:
\[
\text{Net Profit Before Tax} = \text{Net Profit After Tax} + \text{Tax} = ₹ 7,20,000 + ₹ 1,80,000 = ₹ 9,00,000.
\]
3. Return on Investment (ROI):
\[
\text{ROI} = \frac{\text{Net Profit Before Tax}}{\text{Capital Employed}} \times 100 = \frac{₹ 9,00,000}{₹ 20,00,000} \times 100 = 45\%.
\]
Final Answer: ROI = \(\mathbf{45\%}\).