Answer:
X= 618079825.9
Y= 6.18 crystals
Step-by-step explanation:
It takes Lily a crystal to raise 999 zombies.
It will take her x crystals to Raise 617461746174 zombies
Mathematically
One crystal= 999 zombies
X = 617461746174
X=( 617461746174*1)/999
X= 617461746174/999
X= 618079825.9
Again
It took one crystal to raise 999 zombies
It will take y crystal to raise 6174 zombies
Mathematically
One = 999
Y =( 6174*1)/999
Y= 6.18 crystals