Explanation : Let HCF be h and LCM be l. I. Let, numbers be ah and bh. Then abh = and (a + b)h = m => (a — b)h = n Using these ah and bh can be uniquely determined. Thus, I is true II. II. If HCF = LCM, then two numbers are equal and same as HCF or LCM. Thus, II is true. III. LCM/HCF = prime i.e. l/h =P Then one of the numbers is equal to h and other is equal to E. Thus, III is true.