What is twenty thousand more than the smallest digit number

Which of the following is the result of expanding the series

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.

The base of a solid right pyramid is a square with an edge length of n units. the height of the pyramid is n - 1 units. sia (n-1 n