Answer both parts, i will upvote

Hail damage produced an average of 6 abrasions per 200 square feet of roofing in a particular neighborhood. An insurance adjuster was asked to investigate claims from homeowners living in this neighborhood. (a) Find the probability that the adjustor examines less than 50 square feet of roof to find the first abrasion. (b) Find the probability that there are more than 50 abrasions on a house with a 1500 square foot roof