51 is the product of Rhonda's age and 3.

3R = 51

To find Rhonda's age, we need to divide the given number (51) by the given constant (3).

Rhonda's age = 51 ÷ 3

To perform the division, we simply divide 51 by 3:

Rhonda's age = 17.

Therefore, Rhonda is 17 years old.