posted by Keilaa .
On Friday, a house is haunted by a combined total of 51 ghosts, goblins and ghouls, and there were 1/2 as many ghosts as there were goblins. On Saturday, 2/3 of the ghouls each became a ghost. On Sunday, 11 of the ghosts each became a goblin, and the ratio of ghouls to goblins was then 1/3. At that time how many ghosts were there?