Yes because it can be expressed as a fraction in the form of 210/1
Yes, it is.
-210 is a negative, real, rational integer.
210 is an integer and not a fraction. However, it can be expressed in rational form as 210/1. You can then calculate equivalent rational fractions if you multiply both, its numerator and denominator, by any non-zero integer.
It is a rational number. It can be written as a fraction.
yes
Is 12.05 a rational number or irrational number?
1.96 is a rational number
210 is the 20th triangular number.
It is a rational number, as it can be written as a fraction.
Yes, the sum is always rational.
There is no such thing as a number that is both rational and irrational. By definition, every number is either rational or irrational.
As much as, in these days of uncertainty, anything can be anything. As long as the constraints of a rational number are kept to, a rational number will always remain a rational number.