Question

determine the relation between a,b belongs to r
lcm of a&b =4

Answer 1

Answer:

Answer

We have ∗ defined on the set {1, 2, 3, 4, 5} by 

a∗b= LCM of a and b

Now, 3∗4=12

But 12 is not in set {1, 2, 3, 4, 5}.

Hence, ∗ is not a binary operation.