Brooke has to set up 70 chairs in equal rows gor the class talent show. but there is not room for mor than 20 rows. what are the possible number of rows that brooke could set up?

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.