Short term capital gain u/s 111a

dear Cci members, I have read in PDF file of capital gain tax rate of income tax site that surcharge should charged 10% on income tax if the taxable income of partnership firm is more than 1 crore. firm is having short term capital gain of 30 lacs u/s 111a on sale of equity shares on which stt has been paid.Now my question is that on what rate I should calculate capital gain. If I am charging 16.5% after considering 1.5 % surcharge on 15% capital tax then is it correct???please guide me as soon as possible as I have to file return before 31st July.thanx in advance.