Simple math problem ... Multiply the number of people by 15 inches... Then divide by the number of inches in a mile, for total miles ... Then divide that number by the circumference of the Earth in miles.
Ta da!
Suppose we lined up all the people in the world (about 7.2 billion people). Assume that each person occupied 15 inches of the line. How many times around Earth would they reach? (Earth has a circumference of about 25,000 miles.)
Suppose we lined up all the people in the world (about 7.2 billion people). Assume that each person occupied 12 inches of the line.