# Quiz - Extras 2ΒΆ

A primary school is planning a field trip to the zoo for some of its students. For this, the school can only spend exactly `budget`

units. It is known that the entry to the zoo costs 5 units for children under 12 years old and 7 units for those who are 12 years old or older. Develop the function `maximo_estudiantes`

that receives `budget`

, a positive integer that indicates the budget that the school intends to spend. The function should return a tuple `(p, g)`

with the maximum number of small and large students that the school can take to the zoo considering all values as integers.

Develop the function `a_romano`

, which receives a positive integer `n`

greater than zero. The function should return the conversion of the number from Arabic to Roman numerals. The function should return a string that represents the number in Roman numerals.

Examples:

`a_romano(5)`

-> `"V"`

`a_romano(10)`

-> `"X"`

`a_romano(25)`

-> `"XXV"`

`a_romano(2011)`

-> `"MMXI"`

Develop the function `calcular_pi`

, which receives a positive parameter `n`

greater than 0. The function should calculate the approximate value of `pi`

with `n`

terms, according to the following formula.

`pi = (4/1) - (4/3) + (4/5) - (4/7) ...`

The result should be rounded to 2 decimals and returned as a string.

Examples:

`calcular_pi(4)`

-> `"2.90"`

*Explanation*: The first 4 terms following the formula are: `(4/1) - (4/3) + (4/5) - (4/7)`

which result in `2.895238095`

, rounding to two decimal places the final result would be `2.90`

`calcular_pi(24)`

-> `"3.10"`

`calcular_pi(61)`

-> `"3.16"`

`calcular_pi(100)`

-> `"3.13"`