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: secretary duty 
Words: correspondence, schedule, answer calls, keys, file

SOLUTION: keys

PROBLEM: Category: food 
Words: fortitude, meat, cheese, frank, pork

SOLUTION: fortitude

PROBLEM: Category: accomodation 
Words: flat, condominium, house, mansion, plane

SOLUTION:
plane