1 In a hat there are 20 spheres each marked by a different n

1. In a hat there are 20 spheres each marked by a (different) number between 1 and 20 (namely there are no two spears with equal number). You take out a sphere, and if it is not 13 you return the sphere to the urn. If its 13 you stop. Let X be the random variable that counts the number of trials until you took out 13. What is its distribution?

2. The same question in the case you do not put back the spheres that you take out