What per cent of free s03 can be obtained from 100g oleum, that is labeled with 113.5% h2s04?

Question

To 100 ml of 5M naoh solution density 1.2g/ml were added 200ml of another naoh solution with have a density 1.5g/ml and contains 20 mass percent of naoh. What is the concentration of resulting naoh solution obtained by mixing above two naoh solution

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