Mergers (Solution)

by Dan Zaharopol and David Farhi

Pairs of words can be combined into new words. When two words combine into a new word, you simply replace those words on the list with the new word, and continue until there is only one word remaining (the answer). The combined words fit into the given tree.

The words are combined via generic clue (Mac OS X + 10.0 = Cheetah because Max OS X was called Cheetah), or prepend/append (Stephen + Burger = King because Stephen King and Burger King are both things).

Windy + City = CHICAGO (clue)
Stephen + Burger = KING (append)
Dr. Horrible + Damsel = PENNY (clue)
Twenty + Point Count = SCORE (double association)

Aardvark + King = ARTHUR (double association)
Chicago + Rapid Transit = L (clue)
Nadia + Score = 10.0 (clue)
Penny + Policeman = COPPER (double association)

Roman + L = FIFTY (clue)
10.0 + Max OS X = CHEETAH (clue)

Fifty + Element = TIN (clue)
Arthur + Cheetah = CHESTER (prepend)

Tin + Copper = BRONZE (clue)

Bronze + Information = AGE (append)

Chester + Age = MAN (prepend)

The answer is MAN. Here is the filled-in tree: