We consider the given reaction H2SO4 + 2 NaOH -> Na2SO4 + 2H2O as applies to an acid-base titration.
moles NaOH = c · V = 0.2767 mmol/mL · 25.34 mL = 7.011578 mmol
moles H2SO4 = 7.011578 mmol NaOH · 1 mmol H2SO4 / 2 mmol NaOH
= 3.505789 mmol
Hence
[H2SO4]= n/V = 3.505789 mmol / 39.54 mL = 0.08866 M
The answer to this question is [H2SO4] = 0.08866 M