Question

how to calculate the sum of following five no. 2,6,10,14,18,22,26,30,34,38 will be 100

Answer 1

You can Use the formula given according the Summation of Series Method. Do you know the formula ?

Answer 2

even numbers have sum
\[S_n=2n(n+1)=2n^2+2n\]

Answer 3

ie \[S_n=\frac{n}{2}(2a+(n-1)d)\]
\[a=2,d=2\]