Write an equation of the line passing through the given point that is parallel to the given line

Kia is doing an experiment in science lab.  she is given a beaker containing 100  g of liquid.  the beaker has markings on the side for measuring volume.  the water comes up to the 100  ml mark.  kia puts the liquid on a hot plate by mistake.  by the time she realizes the mistake, half of her liquid has evaporated.  kia still needs 100  g of liquid for her experiment.  to find out how much liquid she has to replace, she needs to re-weigh her liquid.however, the balance she used before is now broken.  the teacher tells kia that she can tell how much water is left by looking.the water now comes up to the 50  ml mark.how much mass does kia's remaining water have?