What do the 6 and the 2 represent in this equation?

Question

Shane gives a thumbs up to 6 of his friends. The next day, each of those friends gives a thumbs up to 2 other friends. The day after that, each person who received a thumbs up on the previous day gives a thumbs up to 2 different friends. The expression 6(2^d) represents this situation. What do the 6 and the 2 represent in this equation?

Answer 1

The equation should be = T = 6(2^d-1)

6 is the first term.

2 is the common ratio