If it takes 5 elves 5 minutes to make 5 dolls, how long would it take 100 elves to make 100 dolls?

5 elves*5 minutes=5 dolls
1 elf *5 minutes=1 doll

so it takes 5 minutes for an elf to make doll

100 elves*100 minutes/5=100*20=2000 dolls in 100 minutes by 100 elves