Question

find sum 7+14+21+26+35+......+350 ​

Answer 1

Answer:

8925

I hope this answer may help you

Answer 2

Answer:

in the question this is in a series

let a= 7 , d = 7 ,an = 350

an = a+( n-1)d

an= 7+7n-7

350 = 7n

n=350/7

n=50

I.e now the sum of this question is

Sn = n/2{2a+(n-1)×d}