To find the sum of the infinite geometric series, we can use the formula:

S = a / (1 - r)

where S is the sum of the series, a is the first term, and r is the common ratio.

In this case, the first term (a) is 1/3 and the common ratio (r) is 1/3.

Plugging these values into the formula, we get:

S = (1/3) / (1 - 1/3)

Simplifying the denominator, we have:

S = (1/3) / (2/3)

To divide by a fraction, we can multiply by its reciprocal:

S = (1/3) * (3/2)

Multiplying the numerators and denominators, we get:

S = 1/2

Therefore, the sum of the series A is 1/2.