Which of the following gives an example of a set that is closed under multiplication?
Answer
A) The product of an even number and an even number
B)The product of a prime number and a prime number.
C)The product of a negative number and a negative number
D) The product of a perfect cube and a perfect cube

Question

Which of the following gives an example of a set that is closed under multiplication?
Answer		
A) The product of an even number and an even number	
B)The product of a prime number and a prime number.		
C)The product of a negative number and a negative number		
D) The product of a perfect cube and a perfect cube

anonymous · Answer

Product of an even number by an even number is closed. 
B) Product of prime number and a prime number is by definition, not a prime number.

anonymous · Answer

thank you c: