Which of the following numbers will replace the question mark (?) in the given series?
13, 21, 33, 54, 91,?

Correct option is B

​To find the number that replaces the question mark (?) in the given series:

Series: 13, 21, 33, 54, 91, ?

Let's analyze the pattern in the series.

1. Find the difference between consecutive terms:

   • $21-13=8$
   • $33-21=12$
   • $54-33=21$
   • $91-54=37$

2. Observe the differences:

   • Differences are: 8, 12, 21, 37.

3. Find the pattern in the differences:

   • The differences themselves form a series: $8,12,21,37$.

   • These are increasing, and the differences between them are:

     • $12-8=4$
     • $21-12=9$
     • $37-21=16$

   • The increments are squares: 2³, 3², 4​².

   • So, the next increment should be  5²​

     5²=25

4. Add this increment to the last difference (37):

   • $37+25=62$.

5. Add this new difference (62) to the last term (91):

   • $91+62=153$.

Final Answer:

(B) 153