countable and uncountable nouns

[parveenjain]

Hi,
I was reading the chapter 10) of MGMAT SC page no. 193.Here it has been mentioned that for knowing the countable or uncountable noun we can perform the counting test, like one hat , two hat etc.
Here it is also mentioned that people and feeling are countable nouns.How these can be justified as counting noun by using this counting method.e.g one feeling, two feeling .. etc.

[aneetha.sampath]

A person's feelings. (countable)
True love. ( uncounted ) because this is fate so we cant imagine.

Feeling can be countable or uncountable:-

Feeling for when you feel something physical is uncountable.

For example:-

I had a tingling feeling in my fingers.
I've got this strange feeling in my stomach.
My toes were so cold that I'd lost all feeling in them.

Feeling to express emotion is countable:-

The feeling of loneliness suddenly overwhelmed him.
Her performance seemed to me completely lacking in feeling.
Some people say that dogs have feelings.

[naifsds]

According to a recent study by the Occupational Safety and Health Administration, the incidence of reported neck and back pain correlate positively to the amount of time spent in sitting positions at work.
A)correlate positively to
B)are correlated positively to
C)correlate positively with
D)correlates positively to
E)correlates positively with (correct)


CAT explanation indicates that the singular subject "incidence" does not agree with the plural verb "correlate.
my question is that i though "and" in "neck and back" would change singular "incidence" to plural "neck incidence and back incidence" which would make it incidences

Thank you
NAIF