# 3, 7, 17, 41, 85, 179

which one term is wrong in the following series?

3, 7, 17, 41, 85, 179

(a) 17

(b) 85

(c) 179

(d) 41

**Answer: (d) 41**

**Solution:-**

3 x 2 + 1 = 7,

7 x 2 + (1 +2) = 14 + 3 => 17, **17 x 2 + (3 + 2) = 34 + 5 => 39**,

39 x 2 + (5 + 2) = 78 + 7 => 85,

85 x 2 + (7 + 2) = 170 + 9 => 179.

Then, the wrong term is 41.

Hence, the correct answer is option (d) 41.