Question 1030750
aRb is NOT reflexive since aRa is not always true, e.g., 3R3 = 3, 10R10 = 10, etc..

aRb is symmetric.  If aRb is true then bRa is also true, since gcd(a,b) = 2 = gcd(b,a).

aRb is NOT transitive, since 4R6 is true and 6R140 is also true, but 4R140 = 4.