Probability: Binomial distribution problem

1. You sit at a park bench while watching your dog wander around a path, beginning at the bench. At every step, your dog has a 2/3 probability of stepping to the left, and a 1/3 probability of stepping to the right (assuming those are the only options, and it can't go forward or backward). After 30 steps, approximate your dog's chance of being at least 15 steps away from you.
2. What is your dog'sexpecteddistance from the bench after 30 steps? 100 steps?