Question

Look at this series $1,1,2,3,5,8,13\dots$what number should come next?

Answer 1

Compute the next number of the series:

Given: $1,1,2,3,5,8,13\dots$

In the given series, we got the third number by adding the first and second numbers.

$1+1=2$

We got the fourth number by adding the second and third numbers.

$2+3=5$

Similarly,

$$\begin{gathered} 3+5=8 \\ 5+8=13 \end{gathered}$$

Thus, the next number of the series will be,

$8+13=21$

Hence the next number of the series will be $21.$