To make purple paint, mya mixed 2/5 cup of red paint with 5/8 cup of blue paint. she wants to make a larger batch of the purple paint. how much red paint is needed to mix one cup of blue paint?

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.