A Student needs to construct a circuit in which there is a voltage drop of 5.0v across a resistance combination, and a total current of 2.0mA flowing through the combination. She has a 4000 Ohm ( 4.0kOhm) resistor which she wants to use and proposes to add another resistor in parallel with it.
a) What value should she use for the second resistor
b) Determine the effective resistance of the combination
The Attempt at a Solution
I have no idea how to work this out. The answers are
a) 6.7 kOhms
b) 2.5 kOhms
I just need to know how to get to that answer