trouble vs. problem

[Elif_]

English Grammar Tests, Elementary Level

ESL/EFL Test #58 "Chit Chat: At the restaurant", question 10

Diner: Right then. If it's not too much .......... Please bring me a cup of coffee.

(a) difficulty
(b) problem
(c) hardship
(d) trouble

English Grammar Tests, Elementary Level

ESL/EFL Test #58 "Chit Chat: At the restaurant", answer 10

Diner: Right then. If it's not too much trouble. Please bring me a cup of coffee.

Correct answer: (d) trouble

Your answer was: incorrect
Diner: Right then. If it's not too much problem. Please bring me a cup of coffee.
_________________________

Why the answer is 'trouble' rather than 'problem'?
Thanks for your explanation.

Elif

[Mister Micawber]

.
Problem is a countable noun; trouble can be, as here, uncountable.

(The phrase, 'if it's not too much trouble', is also a set expresssion.)
.
_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mister Micawber

[rebecca]

why don't we use "differenty"?
thank you.
_________________
I love everyone here!

[Mister Micawber]

.
'Differenty' is not an English word.
.
_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mister Micawber

[rebecca]

Sorry, I mean why don't we use "difficulty"?
Sorry once again.
_________________
I love everyone here!

[Mister Micawber]

.
'Difficulty' would fit grammatically, but the common expression is 'if it's not too much trouble...'.
.
_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mister Micawber