Whack-A-Mole (MIT Mystery Hunt 2020)

MIT Mystery Hunt 2020
Author(s)Yar Woo, Ian Tullis
AnswerClick to revealHEADKNOCKER
No. solves59
No. total guesses111

Whack-A-Mole is an interactive puzzle from the Spaceopolis round of the 2020 MIT Mystery Hunt, involving a conceit similar to the namesake arcade game.

Puzzle Elements[edit | edit source]

Interactive - The puzzle is an applet implementing a variation of Whac-a-Mole on an 18x9 square grid. Each level provides a number and the same set of moles to whack.


Knowledge Required (Periodic Table) - Looking up the first number reveals it to be the standard atomic weight of tungsten. A further check on the dimensions of the board reveals that it's about the perfect size for a periodic table (18 columns for groups, 9 rows for periods including the lanthanides and actinides), and that tungsten just so happens to be on a square with a mole. Hitting this mole (and no others) advances the level. (This is made explicit at Level 2.)

Hint in Title - "Mole", as it turns out, doesn't just refer to the animal—a "mole" is a unit for the amount of a particular substance needed to have a weight matching its atomic weight in grams.

Arithmetic Reasoning - At around level 1-3, the puzzle asks for a value that is actually the sum of two elements' atomic weights. Both must be hit to advance the level. Level 2 introduces a further twist: moles with glasses are negative numbers, instead subtracting their value from the total.

Elemental Spelling - Level 3 instead sets the target to a word; each one can be spelled with the chemical symbols of elements marked with moles. These must be hit in order. The Final Level is similar, but doesn't provide its target and reintroduces the aforementioned glasses moles (which remove their letters from the word). The word obtained from this is, of course, the final answer...

Asked and Answered - ...an answer fitting for a puzzle themed around Whac-a-Mole.