$\text{100}\text{g}$ of liquid $\text{A}$ (molar mass $\text{140}\text{g}{\text{mol}}^{-\text{1}}$) was dissolved in $\text{1000}\text{g}$ of liquid $\text{B}$ (molar mass $\text{180}\text{g}{\text{mol}}^{-\text{1}}$). The vapour pressure of pure liquid $\text{B}$ was found to be $\text{500}\text{torr}$. Calculate vapour pressure of $\text{A}$ (in torr) the solution if the total vapour pressure of the solution is $\text{475}\text{torr}\text{.}$