In an electric circuit, two resistors with resistances 3ohm and 5 ohm are connected in parallel. In this case, if R is the combined resistance of these two resistors, then the reciprocal of R is equal to the sum of the reciprocals of two resistors. What is the value?  Choose the most appropriate option.
A) 15 ohms	B) 15 / 8 ohms	C) 1 / 8 ohms	D) 8 / 15 ohms	E) 8 ohms

Rationale: the wording is a bit confusing , though basically we are told that 1 / r = 1 / 3 + 1 / 5 , from which it follows that r = 15 / 8 ohms . answer : b .
Answer: B