HI dHIVYA,
My suggestion is dont leave any topics. Get very thorough either with info tech or SM. Be very sure abt d flowchart and Glossary of technical computer terms. Read d terms again and again. In SM its not necesary to reproduce d exact terms.But in info its hard to write on own. So if ur thorough wid Sm u cover 50 marks..With flowchart and Glossary of d terms u cover 20 marks. So u can easily cover 70 marks..Rest u can plan it and learn.K. Actually dont feel ok wid costing and tax.I mean dont take it easier.Practice Sums on total income computation and costing probs..K all d very best for ur xams..