Blake and Roy have 100 postcards together. Roy has 60 fewer postcards than Blake. How many postcards are in Roy's collection? How many postcards are in Blake's collection?

Two cyclists 84 miles apart start riding toward each other at the same. one cycles 2 times as fast as the other. if they meet 4 hours later, what is the speed (in mi/h) of the faster cyclist?

Select all the statements that apply to this figure

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