Question

Which sets of numbers are closed under subtraction?

Choose all answers that are correct.
A.
odd natural numbers
B.
rational numbers
C.
{0, 1}
D.
{0, 1, 2}
sorry for bugging you i just don't get it

Answer 1

The answer is:

B.
rational numbers

Because if you perform subtraction in a set of rational numbers, the result you get would still be a rational number.

This does not apply to the other sets.