Write a function, mean that takes two numbers and returns their mean.

Example:
>>> mean(3, 5)
4.0

Write a function, square that takes a number and returns its square.

Example:
>>> square(3)
9

Write a function, square_of_mean, that takes two numbers and returns square of their mean.

Example:
>>> square_of_mean(4, 6)
25.0

Restriction: You cannot use *. + or / inside this function's body

Define a function max_of_two, that takes two numbers, a and b, and returns the larger of the two numbers.

Restriction: You cannot use max or min functions.

Define a function, max_of_four, that takes four numbers, w, x, y and z, and returns the largest of the four numbers.

Restriction: You cannot use max, min or any relational operator (<, >=, ...).

Complete execution flow of the following program

Write a function late, that takes an integer, minutes, and returns True if it is greater than or equal to 5, and False otherwise.

Write a function evaluate_lateness, that takes an integer, minutes and:
  - It returns "good" if minutes is less than 5
  - It returns "late" if minutes is between 5 and 9 (including both)
  - It returns "too late" if minutes is between 10 and 14 (including both)
  - It returns "unacceptable" if minutes is greater than or equal to 15

Restriction: You CANNOT use any relational operator inside this function's body (<, >, !=, ...).

Write a function, pow, which takes two numbers as arguments, x and y and returns x to the power of y

Write a function, multiply, which takes two numbers as arguments, a and b and returns their product.

Write a function, that takes two numbers, num1 and num2, and returns (num1 ** num2) * num2.

Restrictions:
  - You cannot use ** or * inside this function's body
  - You should use pow to calculate num1 ** num2 and multiply to calculate result of power * num2.

Write a function that takes two positive integers, n and m, and returns sum of all numbers between 1 and n that are fully divisible by m. Example:

>>> sum_of_divisibles(6, 3)
9
>>> sum_of_divisibles(10, 4)
12

Define a function, divisible, which takes two number, n and m, and returns True if n is divisible by m, False otherwise. Example:

>>> divisible(4, 2)
True
>>> divisible(5, 2)
False

Define a function, divisibles_prod, which takes one positive integer, x, and returns production of all odd numbers between 1 and x (not including x). Example:

>>> divisibles_prod(5)
3
>>> divisibles_prod(6)
15

Restrictions:
  - You cannot use %

A taxi charges:
  - $4 for the first km
  - $2 for each km from 2 to 10
  - $1.50 for each km beyond 10

Write a function that takes the number of kilometers traveled and returns the total fare. Example:
>>> taxi_meter(1)
4
>>> taxi_meter(2)
6
>>> taxi_meter(10)
22
>>> taxi_meter(15)
29.5