Three numbers are in the ratio. 1/2:2/3:3/4. If the difference between the greatest number and the smallest number is 33, the HCF of the three numbers is:

Answer: Option C

Three numbers $$=\left(\frac{1}{2}:\frac{2}{3}:\frac{3}{4}\right)\times 12$$
I : II : III = 6 : 8 : 9
Difference between largest and smallest number is 33
9x - 6x = 33
3x = 33
x = 11
I : II : III = 6 × 11 : 8 × 11 : 9 × 11 = 66 : 88 : 99
HCF of three numbers [66, 88, 99] = 11