MTM and margin calls on Bank Nifty

A trader sells 3 lots (90 units) of Bank Nifty Dec futures at 58,244.00. The initial margin is 12% of entry notional (hypothetical). The next five settlement prices are 58,500, 58,900, 59,400, 58,800 and 58,100. (a) Compute the daily MTM cash flows. (b) Under the Indian regime (every loss called in cash, maintenance = initial), compute each day's call and the closing balance. (c) Repeat under a CME-style rule with maintenance at 75% of initial margin. (d) Compute the final P&L and the return on margin. How much cash did the trader have to find under (b) during the first three days, compared with the final P&L?