Countable and Uncountable Noun

1) a few. Minutes can be counted like 1 minute, 2 minutes..... so it is a
countable noun. 'a little' is for uncountable and 'a few is for countable. Therefore, the answer is 'a few'.

2) plenty of.
plenty- countable
a large amount of - uncountable

3)several.( There is NO adjective like 'servant'. 'servant' means a person who
works for you.)
several- countable
much- uncountable

4) a large number of.
a large number of- countable
a great deal of- uncountable

5) a large amount of
a large number of- countable
a large amount of - uncountable

6) a lot of
a great deal of- uncountable
a lot of - uncountable + countable

P.S. 'some' is both countable and uncountable.

1. They only talked for a few minutes. (minute is countable noun)

2. He keeps plenty of fish in the aquarium. (fish is countable noun)

3. The farmer has several pigs on his farm . (pig is countable noun)

4. He has collected a large number of stamps. (stamp is countable noun)

5. There is a large amount of flour in the sack. (flour is uncountable noun)

6. There are a lot of ants on the tree. (ant is countable noun)
 
"A lot of" can be used for both countable noun and uncountable noun.
 Many, few and "a large number of" are used for countable noun.
Much, little and "a large amount of" are used for uncountable noun.