The HCF of two numbers is 21 and their LCM is 221 times the HCF.  If one of the numbers lies between 200 and 300, then the sum of digits of that number is:

9 12 15 18

12

HCF = 21 Let numbers are, 21x and 21 y              [x and y are coprime numbers] LCM = HCF × 221 ⇒ xy = 221 ⇒ Let x = 13 & y  = 17 21 × 13 = 273 (lies between 200 & 300) ∴ sum of digits ⇒ 2 + 7 + 3 = 12