1,6,15,(...),45,66,91

Answer: Option B

Explanation:

Please check, given sequence is combination of two seies
[Note: Usually when terms are more than 5, then chances are there that it may contain 2 series.]

Series 1 = 11, 17, 23
Series 2 = 12, 18, 24

So there is pattern +6 in each term
Next term will be 23+6 = 29

Answer: Option A

Explanation:

Please look carefully at the series, its pattern is,
-1, +2, -1, +2, -1, so next will be +2
23+2 = 25

Answer: Option C

Explanation:

Pattern is *2, *3, *4
So next number is the series will be *5
24*5 = 120

Answer: Option B

Explanation:

Each number in the series is the preceding number multiplied by 3 and then decreased by 2.

Answer: Option C

Explanation:

Pattern in the series is +4, +8, +12, +16.
Next term will be 45 + 20 = 65