**Force of Attraction between Point Charges**

The force of attraction between two point charges can be determined using Coulomb's Law. According to Coulomb's Law, the force of attraction or repulsion between two point charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them.

Let's assume that the two point charges have magnitudes q1 and q2, and they are placed at a distance d apart. The force of attraction between them is given by:

F = k * (q1 * q2) / d^2

Where F is the force of attraction, k is the electrostatic constant, q1 and q2 are the magnitudes of the point charges, and d is the distance between them.

**Determining the New Distance**

Now, we need to find the new distance at which the force of attraction will be f/3. Let's call this new distance d'.

According to Coulomb's Law, if the force of attraction is f between two point charges at a distance d, then at a new distance d', the force of attraction will be f/3. Mathematically, this can be represented as:

f/3 = k * (q1 * q2) / d'^2

To find the new distance d', we can rearrange the equation as follows:

d'^2 = (k * (q1 * q2)) / (f/3)

d'^2 = (k * (q1 * q2)) * (3/f)

d' = √((k * (q1 * q2)) * (3/f))

Thus, the new distance d' at which the force of attraction will be f/3 can be calculated using the above formula.

Note: It is important to mention that the medium in which the charges are placed should remain the same, as the electrostatic constant 'k' depends on the medium.

In conclusion, to find the distance at which the force of attraction between two point charges is f/3, we can use the formula d' = √((k * (q1 * q2)) * (3/f)). By plugging in the values of the magnitudes of the charges and the initial force of attraction, we can calculate the required distance.