In an electric circuit, two resistors with resistances x and y are connected in parallel. If R is the combined resistance of these two resistors, then the reciprocal of R is equal to the sum of the reciprocals of x and y. What is R if x is 5 Ohms and y is 6 Ohms?
Select the correct option.
A) 7/30	B) 11/30	C) 11/15	D) 30/11	E) 15/11
1/R = 1/x + 1/y   1/R = 1/5+1/6 = 11/30   R = 30/11   The answer is 30/11.
<result>D</result>
In an electric circuit, two resistors with resistances x and y are connected in parallel. If R is the combined resistance of these two resistors, then the reciprocal of R is equal to the sum of the reciprocals of x and y. What is R if x is 5 Ohms and y is 6 Ohms?