28.Please consider this sentence
a) I have a black and white cat.
Here I mean that I have one cat that is partly black and partly white.
Now, consider this sentence
For example : I have a black and a white cat.Here I mean that I have two cats one is black and the other white. Hence the rule is that when two or more adjectives qualify the same noun, the article is used before the first adjective only. But when they qualify different nouns, the article is used before each adjective separately.
Consider one more example.
a)The President and Chairman is absent.
b)The President and the Chairman are present.Sentence a means that only one person isacting as presidentas wellas chairman. Sentence b means that two differentpersons are acting as the President and the Chairman andboth the persons are present