Question

find the sum of first 24 terms of the list of number whose nth term is given by An =2n​

Answer 1

QUESTION :-

Find the sum of first $24$ terms of the list of number whose nth term is given by $a_n =2n$

ANSWER:-

Data :- $a_n=2n$

To find :-  $S_2_4$

Proof :-

$a_1=2(1) = 2\\\\a_2=2(2)=4$

Common difference (d)

$\\\\=a_2-a_1 \\ \\ = 4-2\\\\=2$

$S_n=\frac{n}{2} (2a+(n-1)d)$

$S_2_4 = 12 (2(2)+23(2))$

     $=12(4+46)\\\\=12(50)\\\\=600$

∴ $S_2_4 = 600$