They lived in America They both hunted
Answer: Reciprocal altruism
Explanation:
When you out your time and effort in doing something for someone and you also expect that they will also do that in return this is called reciprocal altruism.
It is like giving back just as someone has given to you .
I do you a favour and you also do me a favour when I am in need of a favour.
Coral helps Alex to study for her physics exam, she can do the same thing by helping him now study for his genetic exam as he also did out his own will for her.
They used palm leaves, clay, animal skin and paprus.
Nubia was first mentioned by ancient egyptioan trading accounts in 2300 BCE.
Ans
faster runner will have to wait 5 min 4.55 s for the slower runner to cross the finish line in 5km race