Respuesta :
Answer: Option 'B' is correct.
Step-by-step explanation:
Since we have given that
Total number of elements a set has = 6
Number of elements in each subsets has = 3
We need to find the number of subsets of three elements each exist in a set of 6 elements.
So, we will use "Combination ":
[tex]^6C_3=C(6,3)=\dfrac{6!}{3!\times 3!}=20[/tex]
Hence, Option 'B' is correct.