Final answer:
The underlined noun 'computer' in the sentence 'He used the computer to find more information' is countable because it can be counted with numbers and has a singular and a plural form.
Step-by-step explanation:
In the provided sentence, 'He used the computer to find more information.', the underlined noun 'computer' is a countable noun. Countable nouns are essentially items that you can count using numbers. They have a singular and a plural form. In this case, you can have one computer, two computers, three computers, and so on, making 'computer' a countable noun.
Learn more about Countable and Uncountable Nouns