Hadith.3052 - Wuhayb ibn Hafs narrated from Abu Abdullah عليه السلام who said:
"A cow or a camel suffices for seven individuals, whether they are from one household or from different ones."
It is also narrated that a camel suffices for ten separate individuals, and if sacrificial animals are scarce, a single sheep suffices for seventy people.
Regarding the eligibility of sacrificial animals:
Only a camel that has completed five years and entered its sixth year is acceptable.
From goats and cows, a two-year-old (having completed one year and entered the second) is acceptable.
From sheep, a one-year-old lamb is acceptable.
