Question

llfind the sum of 6 + 13+20.......+97​

Answer 1

Answer

HELLO

Step-by-step explanation:

a=6 and d=7

97=a+(n-1)d

97=6+(n-1)7

n-1=13

n=14

so, sum= (n/2)×(2a+(n-1)d)

= 7×103

= 721