TASK DEFINITION: Given a category and a set of five words, find the word from the set that does not belong (i.e. is the least relevant) with the other words in the category. Words are separated by commas.
PROBLEM: Category: type of rigidity 
Words: tough, taut, rough, amalgamated, firm

SOLUTION: amalgamated

PROBLEM: Category: chocolate food 
Words: brownies, falsification, fudge, rich, heavy

SOLUTION: falsification

PROBLEM: Category: mode of transportation 
Words: flap, bike, dangle, fly, drive

SOLUTION:
dangle