Write a Python program using classes and user$-$defined functions to display the ${50}^{th}$ Fibonacci number, assuming that the first Fibonacci number is $0.$

Write a Python program using classes and user$-$defined functions to display each number traversed when you do the $3n+1$ sequence for $n=19.$

Write a Python program using classes and user$-$defined functions to display the leap years between $1850$ and $1950($both end years inclusive$).$

Write a Python program using classes and user$-$defined functions to display a word$-$frequency table of different words appearing in a text file $($case$-$sensitivity need not be considered$).$

Write a Python program using classes and user$-$defined functions to display the Factorials of all positive integers between $10$ and $15($both inclusive$).$

Write a Python program using classes and user$-$defined functions to $($a$)$ add two complex numbers $($b$)$ multiply two fractions. You need to do this using constructors and use the dot operator to access the method using an object.