7y means *Algebra.*
A. 7 plus y

B
7 tens and y ones

C
7 times y

D
7 divided by 7

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