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 3 Ohms and y is 5 Ohms?
Select:	A) 15/8	B) 3/8	C) 5/8	D) 7/15	E) 8/15
1/R = 1/x + 1/y   1/R = 1/3+1/5 = 8/15   R = 15/8   The answer is 15/8.
<result>A</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 3 Ohms and y is 5 Ohms?