turkey-yks 2017 Q16

turkey-yks · Other · ygs Not Maths
If the number of elements of a set is an element of that set, then this set is called a "mysterious set".
For example; $K = \{ 3,4,5 \}$ is a mysterious set.
Accordingly, how many subsets of the set $\mathrm { A } = \{ 1,2,3,4,5,6 \}$ are mysterious sets?
A) 16 B) 24 C) 32 D) 40 E) 48
If the number of elements of a set is an element of that set, then this set is called a "mysterious set".

For example; $K = \{ 3,4,5 \}$ is a mysterious set.

Accordingly, how many subsets of the set $\mathrm { A } = \{ 1,2,3,4,5,6 \}$ are mysterious sets?

A) 16
B) 24
C) 32
D) 40
E) 48