A Bag contains 8 red blocks, 10 purple blocks and 12 blue blocks. You randomly select blocks and then replace them 120 times. How many times can you expect to choose a red block?​

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.