What is countable set with example? - TimesMojo

Determine whether each of these sets is countable or uncountable. For those that are countably infinite, exhibit a one-to-one correspondence between the set of positive integers and that set. a) all bit strings not containing the bit 0 b) all positive rational numbers that cannot be written with denominators less than 4 c) the real numbers not containing 0 in their decimal rep- resentation d) the real numbers containing only a finite number of Is in their decimal representation | Numerade

What are Raina and Jadeja?