Resistors connected in parallel If two resistors of R1 and R2 ohms are connected in para...

Resistors connected in parallel If two resistors of R1 and R2 ohms are connected in parallel in an electric circuit to make an R-ohm resistor, the value of R can be found from the equation

If R1 is decreasing at the rate of 1 ohm/sec and R2 is increasing at the rate of 0.5 ohm sec, at what rate is R changing when R1 = 75 ohms and R2 = 50 ohms?