When of benzoic acid ( ) is dissolved in of benzene, it shows a depression in freezing point equal…

When $2\text{ g}$ of benzoic acid ($\text{C}_6\text{H}_5\text{COOH}$) is dissolved in $25\text{ g}$ of benzene, it shows a depression in freezing point equal to $1\cdot62\text{ K}$. Molal depression constant for benzene is $4\cdot7\text{ K kg mol}^{-1}$. What is the percentage association of acid if it forms dimer in solution?