Let R be the relation on Z defined by R = {(a, b): a, b ∈ Z a - b is an integer}. Find the domain and range of R.
If a=pl.qm.rn and b=px.qy.rz where p,q,r are primes and p<q<r and l,m,n,x,y,z are all natural numbers. Given HCF = p2.q3.r and LCM = p3.q4.r3, which one of the following is NOT true?