Answer:
First, an irrational number is a number that has infinite digits after the decimal point, in such way that those digits do not form any pattern.
The irrational set is called a dense set, wich means that in between two elements of the set, we can find infinite other elements of the set.
For example, between 1 and 2, we have
1.12312412513513532....
1.123224124312432432....
and between those two numbers, we can find infinite irrational numbers, and so on.
Then between -12 and +49, we have infinite irrational numbers.