Question

Observe the series $1,11,21,31,41,51...$ and write the generalised formula.

Answer 1

For writing the generalised formula :

Given series $1,11,21,31,41,51...$

$$\begin{gathered} 10\times 0+1 \\ 10\times 1+1 \\ 10\times 2+1 \\ 10\times 3+1 \\ 10\times 4+1 \\ 10\times 5+1 \\ ...... \end{gathered}$$

We see that we can find other terms of series by the following generalised formula :

$10\times n+1$, where $n$ denotes the term number and $n=0,1,2,3,4.....$

Hence , the above is the required answer.