If A = $$\Large \{ x : x = 4n+1, 2 \le n \le 5 \}$$ then number of subsets of A is:
 A) 16 B) 15 C) 4 D) none of these

 B) 15

Given that $$\Large A = \{ x:x=4n+1;\ 2 \le n \le 5 \}$$

Number of elements in set A is 4 ,

So, number of proper subsets = $$\Large 2^{4} - 1 = 15$$.

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