# GeekDad Puzzle of the Week: The Whatzis – Solution

Congratulations to Christopher Sniezek who demonstrated the technical wizardry of Augra herself and gets a \$50 gift code to ThinkGeek! Thanks to all who submitted answers. Check the solution for your code for \$10 off your next \$30 ThinkGeek purchase. Solution after the jump.

Special thanks to ThinkGeek for providing our prizes!

Your brilliance has created another remarkable device. Your investors are going to love this one but there’s a problem. Your oldest daughter comes upon you looking worried. "What’s wrong, Dad?" she asks.

"Well, I’ve got this remarkable invention but it’s subject from time to time to three faults: the plasma pressurizes; the sprockets stick;
and the torque rings fall off."

"That’s terrible!"

"Yes, but in trying to solve this trouble, I’ve made several observations:

When the seal is removed, button B is pressed, and the lever marked
"Forward" is pulled back, the engine overheats and the phase inducer shakes. The pressing of button B, the release of the safety catch, and a firm tap on the cooling tiles are accompanied by a shaking phase inducer and the ocular interface turning blue. If the seal is removed, cooling tiles tapped, and the Forward lever pulled back, the engine overheats and the ocular interface turns blue. When the safety catch is released, cooling tiles tapped, and the Forward lever pulled back, the ocular interface turns blue. When the engine overheats and ocular interface turns blue, the plasma pressurizes. If the phase inducer shakes and the ocular interface turns blue, the sprockets stick and the torque rings fall off. [sigh]"

Your daughter thinks for a moment. "Well, Dad, working under the assumption that the various events each have single causes, not two or more in conjunction, I think I know exactly how to cure your device."

What does your daughter come up with, i.e., what would you do to be certain of curing your device of its three faults?

Solution
So says your daughter: "Daddy, to prevent the plasma pressurizing, refrain from removing the seal, which will prevent the engine from overheating. To prevent the sprockets from sticking and the torque rings from falling off, refrain from pressing button B. This will prevent the phase inducer from shaking."

Put the data in a table/diagram of sorts illustrating what we know:

Keep in mind that you can figure "if A then B" but you cannot also deduce "if not A then not B," but we can deduce "if not B then not A."

Conditions 5 and 6 are the only ones that give direct information about the three faults we are investigating. From 6 we deduce that neither P.I. nor Blue are the cause of Plasma. From 5, Engine is the cause of Plasma. Neither Engine nor Blue are the cause of Sprockets or Rings. From 6, P.I. is cause of Sprockets and P.I. is the cause of Rings.

From 2 and 4, neither Button nor S.C. nor Tiles nor Lever can be the cause of Engine.

From 1 and 3, Seal is the cause of Engine.

Consider P.I. From 3 and 4, neither Seal, Tiles, Lever, nor S.C. can be the cause of P.I. From 1 and 2, Button must be the cause of P.I.

You give your girl a kiss on the forehead and praise her for being a chip off the ol’ block.

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