Question

Find the sum of the terms of the arithmetic sequence. 1, 7, 13, 19, . . ., 109 n = 19

A. 2204

B. 2090

C. 1045

D. 1102

Answer 1

solution
a=1 , d=7-1=6, n=19
and the formula of A.Sequence is
an=n\2{2a+(n-1)d}
now put in it
an=19\2{2(1)+(19-1)6}
an=19\2{2+(18)6}
an=19\2{2+108}
an=19\2{110}
since,110\2 =55
an=19(55)
an=1045
this the answer
i mean C is correct

Answer 2

Thanks