A sample of H2SO4 is titrated with 30.0ml of 0.150M NaOH.Calculate the concentration of H2SO4

You're missing some information; namely, how much H2SO4 was used. Here is how you work the problem.

.......................H2SO4 + 2NaOH ==> Na2SO4 + 2H2O
mols NaOH used = M x L = 0.150 M x 0.030 L = 0.0045
Using the coefficients in the balanced equation, mols H2SO4 = 1/2*moles NaOH = 1/2 x 0.0045 = 0.00225
Then M H2SO4 = mols/L = 0.00225/L H2SO4 = ?