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: chocolate food 
Words: fudge, tart, chocolate cake, falsehood, cupcake

SOLUTION: falsehood

PROBLEM: Category: animals 
Words: duck, jog, cat, pig, mallet

SOLUTION: jog

PROBLEM: Category: mode of transportation 
Words: train, spider, wave, fly, drive

SOLUTION:
spider