Place the before little.

The sentence is talking about the limited knowledge of computers that the person had, which turned out to be helpful in getting a job. However, the way this idea is expressed in the sentence is incorrect. Let's break down the sentence to understand the error:

• Part 1: "Little knowledge" - This phrase is correct and means 'a small amount of knowledge'.
• Part 2: "of computers that she possessed" - This part is also grammatically correct and describes the type of knowledge the person had.
• Part 3: "proved a boon for her" - This means that the limited knowledge of computers turned out to be helpful for her in some way.
• Part 4: "in getting job" - This part is incorrect because it should be "in getting a job". This is because 'job' is a countable noun and requires an article before it.

Therefore, the error is in Part 1, and the corrected sentence would be:

"A little knowledge (1) / of computers that she possessed (2) / proved a boon for her (3) / in getting a job. (4) / No Error (5)"

Some relevant definitions and formulas:

• Countable noun: A noun that can be counted and has both singular and plural forms. Examples: book, chair, cat.
• Uncountable noun: A noun that cannot be counted and does not have a plural form. Examples: water, air, music.
• Article: A word that is used before a noun to indicate the type of reference being made to the noun. There are two types of articles - definite (the) and indefinite (a/an).
• "A little" vs "Little": "A little" means 'some' or 'a small amount', whereas "little" means 'not much' or 'hardly any'.