Mass = 98% i.e 98 gms of H₂SO₄ is present in 100 g of solution 

Density = 1.84g/cc

Density = $\frac{\mathrm{mass}}{\mathrm{volume}}$

Volume = $\frac{100}{1.84}\mathrm{ml}$

Number of moles of  H₂SO₄ =$\frac{98}{98}=1 \mathrm{mole}$
Molarity = $\frac{\mathrm{moles} \times 1000}{\mathrm{volume} \mathrm{of} \mathrm{solution} \mathrm{in} \mathrm{ml}}$

Molarity = 
$\frac{1\times 1000\times 1.84}{100}=18.4$M