Simplify the following: 1.√7 × √7
2.√18 × √2
3.√45
4.√50/5
5.2√2 × 4√5
6.√48 - √12
7.(2-√3) (1+√3))

Identify all the cases where non-probability sampling is used when attempting to study the characteristics of a large city. studies on every subject in the population divide a population in groups and obtain a sample studies with a limited amount of time demonstrate existing traits in a population studies with the nth person selected