Every weekday Rosa drives alone over the bridge into the city and pays a toll. Every evening she drives alone back over the same bridge and pays nothing. She has no discount. How?
Hint: Look at how the toll booths are set up.
AnswerSome bridges, like the Golden Gate Bridge, only charge a toll in one direction.Charging one direction double does the same job with half the toll booths.
Ruth was born, lived and died in the same farmhouse and never left the United States, yet she was born outside every U.S. state and died inside one. How?
Hint: Think about American history.
AnswerHer home was in a territory, like Arizona before 1912, that later became a state.Several states, including Arizona, New Mexico and Oklahoma, were U.S. territories within living memory.
Mia's flight left Tokyo at 9 p.m. on a Monday and landed in Honolulu about seven hours later, at 9 a.m. on that same Monday. The flight was on time and every clock was right. How?
Hint: Look at a map of the Pacific.
AnswerShe crossed the International Date Line, which put her back into Monday.Flying east across the date line turns the calendar back a day, so a seven-hour flight can land twelve hours 'before' it took off.
Almost every person who ever lived has seen the moon, but only a few dozen people have ever seen its other side with their own eyes. Why?
Hint: Watch the moon for a few nights in a row.
AnswerThe moon always keeps the same face toward Earth, so only astronauts who flew around it have seen the far side.The moon spins exactly once per orbit, so the same side always points at us.
Same airline, same kind of plane, same route: Kim's flight from Los Angeles to New York took about an hour less than her flight home. No delays and no detours. Why?
Hint: Same plane, same pilot, so look outside the plane.
AnswerThe jet stream blows west to east, giving eastbound flights a tailwind and westbound flights a headwind.That high-altitude wind can add or subtract well over 100 mph of ground speed.
On a frosty morning Nina's car warned her that all four tires were low. By afternoon the warning was gone. She never added air and no one touched the tires. How?
Hint: Think about what changed overnight.
AnswerCold air takes up less space, so tire pressure dropped overnight and came back as the day warmed up.Tire pressure falls roughly one pound for every 10 degrees of cooling, which is why warnings pop up on cold mornings.