Favorite Child

Python Puzzles

Back to the Python! homepage

You live in a society where female children are preferred over male children. By law, couples have to conceive children until they produce a female offspring. If their first child is male, they are allowed to have additional children until a female is born. Once a female is born, they are allowed no additional children.

What is the average ratio of females to males in this society?

The ratio will be 50/50.

import random
female = 0
male = 0

for _ in range(10_000_000):

    gender = random.randint(0,1);
    
    if gender == 0: female += 1    

    while gender != 0:    
        male += 1        
        gender = random.randint(0,1)
        
        if gender == 0: female += 1

print('Number of females is ' + str(female))
print('Bumber of males is ' + str(male))

print('Percentage female is ' + str(female/(female+male)))
print('Percentage male is ' + str(male/(female+male)))