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A house was haunted by a combined total of 51 guosts, goblins, and ghouls. On Friday, there were half as many ghosts as there were goblins. On Saturday, two-thirds of the ghouls each became a ghost. On Sunday, 11 of the ghosts each became a goblin, and the ratio of ghouls to goblins became 1 :3. If no other changes occurred, how many ghosts are there?

User Rogerrw
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1 Answer

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Answer: There are 15 ghosts in a haunted house.

Step-by-step explanation:

Since we have given that

Total number of ghosts, goblins and ghouls = 51

On Friday,

Let the number of goblins be x

Let the number of ghosts be


(x)/(2)

Let the number of ghouls be


51-x-(x)/(2)=51-(3x)/(2)

On Saturday,

Two-thirds of the ghouls each became a ghost,

So, it becomes


(2)/(3)* (51-(3x)/(2))=34-x

Now, number of ghost becomes


(x)/(2)+34-x=34-(x)/(2)

and number of ghouls becomes


51-(3x)/(2)-34+x=17-(x)/(2)

On Sunday,

Number of ghosts each became a goblin = 11

So, Number of goblins becomes


x+11

Now, according to question , we have a ratio of ghouls to goblins i.e. 1:3

So, it becomes,


(17-(x)/(2))/(x+11)=(1)/(3)\\\\(34-x)/(2x+22)=(1)/(3)\\\\102-3x=2x+22\\\\102-22=2x+3x\\\\80=5x\\\\(80)/(5)=x\\\\16=x

So, number of ghosts is given by


34-(x)/(2)-11\\\\=23-(x)/(2)\\\\=23-(16)/(2)\\\\=23-8\\\\=15

So, there are 15 ghosts in a haunted house.


User Pedro Alves
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