The investor buys 100 shares at Rs. 200 per share on 60% margin, meaning they invest 40% of the total value (100% – 60% margin). The initial investment is Rs. 80,000 (100 shares * Rs. 200 per share * 40%). When the stock price rises to Rs. 220, the value of the investment becomes Rs. 88,000 (100 shares * Rs. 220 per share). The percentage return on investment is calculated as [(Final Value – Initial Investment) / Initial Investment] * 100, which is [(Rs. 88,000 – Rs. 80,000) / Rs. 80,000] * 100 = 10%.