I guess it's a permutation, if so we have to calculate:
(⁶P₃) / (¹¹P₄):
⁶P₃ = (6!)/(6-3)! = (1.2.3.4.5.6)/(1.2.3) = AFTER simplification =4.5.6 = 120
¹¹P₄ = (11!)/(11-4)!= (1.2.3.4.5.6.7.8.9.10.11)/(1.2.3.4.5.6.7) = 7920
(⁶P₃) / (¹¹P₄) = 120/7920 = 1/66