Question

Javier shared his post with 4 friends, who each shared it with 4 more friends. They continued sharing at the same rate

Answer 1

First, 4 people know the post

Then, those 4 people share it each with 4 people (4 * 4 = 16)

Then, each of those people share it with another 4 people (16 * 4 = 64)

And so on. the function is as simple as: 4^x (4 to the power of x)