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PASSING THE TIME
game the system
THERE’S NOTHING MORE PAINFUL THAN WATCHING TIME PASS DURING A
road trip. Instead, occupy your mind with these logic problems. Then whip them out on future car
rides, and watch your fellow passengers struggle. Hints: In problem one, the Olympian crosses
the bridge three times. In two, Jen and Dan both make one airport pit stop. (Answers on page 122.)Q: A kindergartner, a fifth grader, a high
school track star, and an Olympic sprinter
are all waiting in line at a track-and-field
meet’s food stand. Suddenly, the storm of
the century starts to roll in. The only way
back to the safety of the stadium is across
a wobbly bridge in critical need of repair.
The rickety old thing can handle only two
people crossing at one time. Three runners or even a strong burst
of wind could knock it away entirely. To make matters worse, the
tempest’s dark clouds have blotted out the sun completely. Luckily,
the kindergartner has a flashlight keychain attached to his back-
pack that provides just enough light to travel across safely.
The winds that will take down the structure begin in 17 minutes.
The Olympic sprinter can race across in just one minute, and the
high school track runner can manage in two. But it takes the fifth
grader a plodding five minutes and the kindergartner an even slow-
er 10. Given that the dilapidated bridge can handle just two people
at once and one of the travelers must always have the flashlight in
hand, how can the group get to safety in the allotted time?
Q: An amateur engineer plans to circum-
navigate the equator in an airplane he
designed himself. Unfortunately, when
he built it, he hadn’t planned on using it
for a flight of this nature. So, the plane
holds only enough fuel to make it halfway.
Intent on making this feat a reality, he
built two more identical planes and con-
vinced his two friends, Jen and Dan, to pilot the spare planes and
help him along to achieve his goal. The planes can transfer their
fuel midair at any point during the trip, but there’s a catch: Only
one airport on Earth will allow these homemade airliners to take
off and land—and it happens to be located along the way.
The engineer wants to travel the entire globe without stopping,
and Jen and Dan have agreed to stop, refuel, and follow the engi-
neer in whatever manner necessary to help. It won’t be easy: Each
plane holds 180 gallons of fuel and can travel 1 degree of longitude
(it takes 360 degrees to circle the world) in one minute for every
1 gallon of fuel. How can Jen and Dan help? When should they stop,
transfer fuel to the engineer, and head to and from the airport?by Claire MaldarelliTIME TRIALS A CALCULATED TRIP