Past puzzles

#32 · How many pieces of mail does the US Postal Service deliver per day?
#31 · How many helium party balloons would it take to lift a person?
#30 · How many seconds old is a 30-year-old?play
#29 · How many miles of public roads are in the US?play
#28 · How many Olympic swimming pools would fill Sydney Harbour?play
#27 · How many bones are in an adult human body?play
#26 · How many photos are taken worldwide every day?play
#25 · How much does the Eiffel Tower weigh, in tonnes?play
#24 · How many times does a typical human heart beat in an 80-year lifetime?play
#23 · How many new cars are sold worldwide per year?play
#22 · How many ants are on Earth?play
#21 · How many years would it take to count to one billion, out loud, nonstop?play
#20 · How many gallons of gasoline does the US burn per day?play
#19 · How many people are in the air, flying, worldwide right now?play
#18 · How many thunderstorms are happening on Earth right now?play
#17 · How many piano tuners work in the Chicago metro area?play
#16 · How many books does the Library of Congress hold?play
#15 · How many inches does human hair grow in a year?play
#14 · How many McDonald’s restaurants are there worldwide?play
#13 · How many hairs are on a typical human head?play
#12 · How many liters of water does a person drink in a lifetime?play
#11 · How tall is a stack of one million US $1 bills, in feet?play
#10 · How many commercial flights are airborne over the US at a typical mid-afternoon moment?play
#9 · How many pizzas are sold in the US every day?play
#8 · How many cells are in an adult human body?play
#7 · How many days does it take to thru-hike the Appalachian Trail?play
#6 · How many text and chat messages are sent worldwide per day?play
#5 · How much gold has ever been mined, in tonnes?play
#4 · How much does a typical cumulus cloud weigh, in pounds?play
#3 · How many golf balls would fill a school bus?play
#2 · How many words are in a typical novel?play
#1 · How many breaths does a person take in a day?play