Question

Hi again! i need your help again. please give me some examples for the closure property in this set:
The odd numbers is closed under multiplication.

Answer 1

3 - odd number
5 - odd number

(3) . (5) = 15
15 - odd number

therefore..odd number is closed under multiplication

Answer 2

If by closure you mean for any a,b in A, where A is a set of all odd numbers, a*b is also in A. Then choose two odd numbers such as 7 and 3. 7*3 is 21. Which is also odd. However, picking specific examples doesn't "prove" that odd numbers are closed under multiplication and you would have to prove the general case of a=2n+1 and b=2m+1.