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Laundry hangs outside a college dormitory in Wuhan, China, in 2009.

Quiz: Population 7 Billion—Could We All Fit in One City?

Could all humans fit in one city? Is the most typical person a woman? Get answers in our quiz on the human population reaching seven billion.

For the first time in history, there are now seven billion people living on Earth (or are there?). That number is projected to hit nine billion by 2045. See how much you know about our booming population.

Answers at bottom.

1. On a planet of seven billion people, who is the most typical human?

a. Javanese Indonesian man, 62

b. Punjabi Indian woman, 34

c. Han Chinese man, 28

d. Zhuang Chinese girl, 10

2. If all seven billion people on Earth stood shoulder-to-shoulder, we would fill _________.

a. São Paulo, Brazil

b. Tokyo, Japan

c. Florida

d. Los Angeles, California

3. Life expectancy in an industrialized nation is about ___ years long.

a. 55

b. 70

c. 80

d. 100

4. How many people have ever lived on Earth?

a. 15 billion

b. 55 billion

c. 108 billion

d. 500 billion

5. What percent of all people who've ever been born are alive now?

a. 0.5%

b. 2.0%

c. 6.4%

d. 15%

6. The most populous country today is China. What will it be in 2050?

a. China

b. India

c. Nigeria

d. Indonesia

7. What percent of the world's population is literate?

a. 5%

b. 16%

c. 38%

d. 82%

8. Do most people today live in urban or rural environments?

a. Urban

b. Rural

9. How do most people make their livelihood?

a. Agriculture

b. Services

c. Industry

10. In 2011, there were _______ births per minute around the world.

a. 38

b. 127

c. 266


1. c

According to statistics, a 28-year-old Han Chinese male is now the most typical human on the planet. The world's largest age bracket is 28, the largest ethnic group is Han, the most populous nation is China, and there are 1.01 men in the world for every woman.

2. d

Standing shoulder-to-shoulder, the entire world's population could fit within the 500 square miles (1,300 square kilometers) of Los Angeles.

3. c

A typical life in an industrialized country is now about 80 years long—three decades longer than it was a century ago. In contrast, life expectancy in sub-Saharan Africa is a mere 53 years.

4. c

It's estimated that a total of 108 billion people have lived on Earth.

5. c

Of the 108 billion people that have ever been alive, it's estimated that 6.4 percent of them—seven billion—are alive now.

6. b

According to the Population Reference Bureau (PRB), India will surpass China to become the world's most populous country by 2050. Its projected population: almost 1.7 billion.

7. d

Global literacy is 82 percent. But for those who live where printed materials, even signs or product boxes, are rare, reading is a "use it or lose it" skill.

8. a

As of 2008, the world's population has shifted from mainly rural to more than 50 percent urban. Most urbanites live in cities of fewer than 500,000 people. By 2050, 70 percent of us will be living in urban areas.

9. b

Most people today (40 percent) work in services. A close second (38 percent) work in agriculture, and 22 percent work in industry.

10. c

Every minute, about 266 children were born in 2011—382,351 a day and 139,558,000 for the year.

More 7-Billion Population Coverage