Question

The $8^{th}$ term of the sequence $1,1,2,3,5,8,....$ is

• A. $25$
• B. $24$
• C. $23$
• D. $21$

Answer 1

The correct option is D $21$

The given sequence is a Fibonacci Sequence with the series of numbers:

$1,1,2,3,5,8,.....$

In the above sequence, each of the term is found by adding up the two numbers before it that is:

The third term $2$ is found by adding the two numbers before it $(1+1)$

The fourth term $3$ is found by adding the two numbers before it $(1+2)$,

The fifth term $5$ is $(2+3)$,

The sixth term $8$ is $(3+5)$,

The seventh term $13$ is $(5+8)$ and

The eighth term $21$ is $(8+13)$

Hence, the $8$th term of the given sequence is $21$.