input: from typing import List
  
  
  def generate_sample_data(num_entries: int) -> List:
      """ Generate sample data for a web application using Python's faker library.
      The output should contain three columns of data: name, email, and age.
      >>> generate_sample_data(3)
      [('John Doe', 'john.doe@example.com', 25), ('Jane Smith', 'jane.smith@example.net', 30), ('Bob Johnson', 'bob.johnson@example.org', 45)]
      """
      from faker import Faker
      fake = Faker()
      data = []
      for _ in range(num_entries):
          data.append((fake.name(), fake.email(), fake.random_int(min=18, max=60)))
      return data
output:     from faker import Faker
      fake = Faker()
      data = []
      for _ in range(num_entries):
          data.append((fake.name(), fake.email(), fake.random_int(min=18, max=60)))
      return data