Help with finding the sum of the infinite geometric series?

Question

1:
∞
∑ 60 (1/10) ^k
k = 1

 2:
∞
∑ 3.5^k
k = 1

Answer 1

1.

            (The sum of the infinite geometric series formula = where )   

       (Substitute and in the above formula)

             (Simplify)

.

 

Answer 2

2.

            (The sum of the infinite geometric series formula = where )   

       (Substitute and in the above formula)

             (Simplify)

.

 

Answer 3

1)

Therfore

Sum of infinite sequence is