-12 belongs to negative integers
mixed numbers
The square root of 121 is 11, as (11 \times 11 = 121). Any numbers that are not equal to 11 do not belong to the square root of 121. This includes all numbers such as 10, 12, -11, and any other number that is not 11.
Irrational numbers.
None. There is nobody to whom triangular numbers belong.
Rational numbers.
mixed numbers
The answer is 12 every other numbers are odd numbers, but 12 is an even number
The set of numbers which 3 does not belong is the set of even numbers.
15 because its an odd number whereas 6, 10 & 12 are even numbers.
10 belongs to the set "natural numbers", but it can also belong to whole numbers, and rational numbers
It belongs to any set that contains it: for example, {4.75, -12, pi, sqrt(5), 29}. It belongs to the set of integers which is a proper subset of rational numbers which is a proper subset of real numbers which is a proper subset of complex numbers. So -12 belongs to all the above sets.
Counting numbers
Rational numbers
Irrational numbers.
Any set that contains -1.2, whether finite or infinite. For example, the set consisting of only -1.2 ie {-1.2}, the set consisting of -1.2 and 5 = {-1.2,5}, the set consisting of -1.2 and 3 and sqrt(17) = {-1.2,3,sqrt(17)}, and so on.
odd numbers, perfect square numbers
None. There is nobody to whom triangular numbers belong.