For The Mathematically Inclined

For The Mathematically Inclined

Anil Saigal
03/22/2016

Problem 1

The circumference of the Earth is approximately 40,000 kilometers, and someone has just made a metal band that circles the Earth, touching the ground at all locations. You come along at night and add just 10 meters to its length (one hundredth of one kilometer). It is now one four-millionth longer, and sits magically just above the ground at all locations. How far has it risen?

Problem 2

A swimmer jumps from a bridge over a canal and swims 1 mile upstream. After that first kilometer, he passes a floating cork. He continues swimming for another hour and then turns around and swims back to the bridge. The swimmer and the cork arrive at the bridge at the same time. The swimmer has been swimming with constant speed. How fast does the water in the canal flow?

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Problems from 03/10/16

Problem 1
Two tourists visit the Dutch city of Gouda. During their tour through the center, they spot a cozy terrace. They decide to have a drink and, as an appetizer, a portion of hot "bitterballs" (bitterballs are a Dutch delicacy, similar to croquettes). The waiter tells them that the bitterballs can be served in portions of 6, 9, or 20. What is the largest number of bitterballs that cannot be ordered in these portions?

Problem 2
stream up. After that first kilometer, he passes a floating cork. He continues swimming for half an hour, then turns around, and swims back to the bridge. The swimmer and the cork arrive at the bridge at the same time. The swimmer has been swimming with constant effort. How fast does the water in the canal flow?

Congratulations to Amit Lele, who was the winner of last set of puzzles.

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