Question

Find the $6^{\text{th}}$ number in the following sequence.
$1$ $3$ $5$ $7$ $9$ ______

• A. $10$
• B. $11$
• C. $12$
• D. None of the above

Answer 1

The correct option is B $11$

Given sequence: $1$ $3$ $5$ $7$ $9$ ______

$\bullet$ Difference between $2^{\text{nd}}$ term and $1^{\text{st}}$ term $=3-1=2$
$\bullet$ Difference between $3^{\text{rd}}$ term and $2^{\text{nd}}$ term $=5-3=2$

Therefore, there is a difference of $2$ in consecutive terms, i.e., if we add $2$ with the previous term, we get the next term.

$\therefore$ The $6$th number $=9+2=11$

Hence, option (b.) is the correct one.