Puzzle #186: The Impossible Zoo

Welcome to Gene’s Impossible Zoo. The zoo has some four-legged animals (exactly one-half of the number of two-legged animals). The number of two-leggers is exactly one-half of the number of zero-legged animals (often called fish and snakes). These are all of the animals, and they have a total of 200 legs.

It is not called an impossible zoo for nothing. Why is the description above self-contradictory?

Submit your answer to Gene Wirchenko <genew@telus.net>. Your answer should be in the form of a proof. That means to show how your answer must be correct. The deadline is Wednesday, December 28, 2016 at noon Pacific Time. I will post the answer shortly after.

Have you ever played a long game where two players are competing fiercely and a nasty rules argument gets going?

If you ever wonder why gamers can be so picky on rules, this is part of why. Ambiguous rules make for horrible arguments, and they will happen right when it really matters.

As a gamer, it is not fun to play a long game and get into a situation where two players both think they are right about a rule interpretation, each was counting on his interpretation, and it turns out that both interpretations are valid.

No one ends up happy. If you write rules, please make them as clear as possible.

Odd Language #182: Miles Per Hour

From a USENET post: “At 12 Amps, 110V, a Tesla can charge about 3.5 mph
in a warm garage.”

The issue: “mph” meaning miles per hour does not seem to make sense here, but a later post in the thread explains it: “Not really catchy – we’re trying to describe how many miles worth of driving you can get for each hour of charging. MPH is actually correct, but you have to be aware of the context.” It is MPH: Miles Per [Charge] Hour.

Puzzle #185: Digit Sets

Each digit from 0 to 9 has been put into one of three sets.

Set 1: 0, 6, 8, 9
Set 2: 1, 2, 5, 7
Set 3: 3, 4

The solution has something to do with the shape of the digits. For the exact shapes, think calculator digits.

What is the rule for which set a digit goes into?

Submit your answer to Gene Wirchenko <genew@telus.net>. Your answer should be in the form of a proof. That means to show how your answer must be correct. The deadline is Wednesday, December 21, 2016 at noon Pacific Time. I will post the answer shortly after.