I need help with math please

How do newtons third law of motion demonstrates on a rollar coster

The coverage of a base station of a telecommunication company forms a disk with a radius of (kilometers). let be the distance of a cellphone from a base station. assume that the location of cellphones in use are randomly uniformly distributed within the disk. calculate the mean and variance for the random variable.

You draw a card at random from a deck that contains 33 black cards and 77 red cards.