Sets and Mappings #2 | Rational numbers are countable. Real numbers are uncountable

I this video tutorial you will learn Sets and Mappings, Injective, Surjective and Bijective Mappings, which is the foundation of Measure Theory used in Mathematical Finance. Along with this, you will learn what is a Direct Image, Inverse Image, Pullbacks and its Properties.
In part 2 of these lesson you also will learn Countable and Uncountable sets,
proof of countability of the Set of Rational Numbers and Uncountability of the Set Real Numbers (Cantor Diagonal Argument);