Please help will get brainliest if correct

Which of those sequences is a geometric sequence

Arestaurant gives out a scratch-off card to every customer. the probability that a customer will win a prize from a scratch-off card is 25%. design and conduct a simulation using random numbers to find the experimental probability that a customer will need more than 3 cards in order to win a prize. justify the model for your simulation, and conduct at least 10 trials.

F(n + 1) = f(n) – 8. if f(1) = 100, what is f(6)?