In an electric circuit, three resistors with resistances 2 ohms, 5 ohms and 6 ohms are connected in parallel. In this case, if R is the combined resistance of these three resistors, then the reciprocal of R is equal to the sum of the reciprocals resistors. What is R value? Choose the correct choice from the following answers
A) 13 / 15 ohms  B) 15 / 13 ohms  C) 5 / 8 ohms  D) 3 / 7 ohms  E) 45 / 18 ohms

Rationale: the wording is a bit confusing , though basically we are told that 1 / r = 1 / 2 + 1 / 5 + 1 / 6 , from which it follows that r = 13 / 15 ohms option : a
Answer: A