Which number should be replaced with x in following series :

2, 3, 5, 7, 11, x, 17

Answer: Option D

Explanation:

We can see the given series is in G.P.
as 2*3 = 6, 6*3 = 18, 18*3 = 54
So a = 2 , r = 3
nth term in G.P. is
\begin{aligned}
ar^{n-1} \\
= 2*3{8-1} \\
= 2*3^7 \\
= 2*2187 = 4374
\end{aligned}

Answer: Option B

Explanation:

Above series contains prime number series. So after 11, 13 is next prime number.

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 B

Explanation:

Pattern is +13,+(13*2), +(13*3)
Next will be +(13*4) = 80+52 = 132

Answer: Option A

Explanation:

Series Pattern is +3, +5, +7, +9.

So next number = 25+11 = 36