please explain the difference between 'picture' and 'paint'

[Ginevra]

English Grammar Tests, Elementary Level

ESL/EFL Test #244 "Non-Count and Count Nouns (3)", question 1

I have to buy some .......... I want to change the color of my bedroom walls. This is a non-count noun.

(a) picture
(b) paint
(c) lawnmower
(d) cooler

English Grammar Tests, Elementary Level

ESL/EFL Test #244 "Non-Count and Count Nouns (3)", answer 1

I have to buy some paint. I want to change the color of my bedroom walls. This is a non-count noun.

Correct answer: (b) paint

Your answer was: incorrect
I have to buy some picture. I want to change the color of my bedroom walls. This is a non-count noun.
_________________________

Could you please explain the difference between "picture" and "paint" ?
Thanks a lot

[Beeesneees]

http://www.oxfordadvancedlearnersdictionary.com/dictionary/picture
http://www.oxfordadvancedlearnersdictionary.com/dictionary/paint

Artists may paint a picture.
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"Inside every old person is a young person wondering what happened."
Terry Pratchett

[Mimyamigo]

paint is drawing, picture is after you finish painting its become picture
thank you

[Puppet]

Hello,

But we can say ''painting'', Can't we?
I mean if it was included .. the options. While ''Paint'' was instead as a kind of trap.

[Beeesneees]

We cannot use 'painting' in the test question.

You want to buy paint so that you can use it to change the colour of the walls.

Buying a painting will not help you change the colour of the walls themselves - it will only provide you with something to put on the wall!
_________________
"Inside every old person is a young person wondering what happened."
Terry Pratchett

[Puppet]

I'm sorry, The fault was mine.

I didn't read it completely.

[Beeesneees]

No problem, Puppet. It happens to us all.
_________________
"Inside every old person is a young person wondering what happened."
Terry Pratchett