**Solution-**

Volume of water $=\frac{\text { mass }}{\text { density }}$ $=\frac{56 \mathrm{~g}}{1.0 \mathrm{~g} \mathrm{~cm}^{-3}}=56 \mathrm{~cm}^{3}=56 \mathrm{~mL}$

Volume of ethanol $=0.17 \mathrm{~L}=0.17 \times 1000 \mathrm{~mL}=170 \mathrm{~mL}$

$\therefore$ volume of solution $=(56+170) \mathrm{mL}=226 \mathrm{~mL}$

$\therefore$ concentration per cent by volume

$$

=\frac{56}{226} \times 100=24.78 \%

$$