A liquid at  $30°C$  is poured very slowly into a calorimeter that is at temperature of $110°C$  . The boiling temperature of the liquid is  $80°C$  . It is found that the first 5 g of the liquid completely evaporates. After pouring another 80 g of the liquid the equilibrium temperature is found to be  $50°C$ . The ratio of the latent heat of the liquid to its specific heat will be  $x\times 90°C$ ,  then   $x=$   ________ [Neglect the heat exchange with surrounding]