Circuit/Current/Resistance Problem

[blackout77]

I need help finding the current in a series circuit with 3 resistors! I have Vs = 12V, R1 = 220ohms, at R2 has a voltage drop = 7V, and at R3 has a voltage drop = 2.5V. How do I find the current? I Know I have to add up all the resistors but how do I find the other 2 unknown resistors?

 

[berkeman]

I need help finding the current in a series circuit with 3 resistors! I have Vs = 12V, R1 = 220ohms, at R2 has a voltage drop = 7V, and at R3 has a voltage drop = 2.5V. How do I find the current? I Know I have to add up all the resistors but how do I find the other 2 unknown resistors?

Welcome to the PF.

Think of those two resistive voltage drops just as voltage sources for a moment. What is the net voltage that is across the 220 Ohm resistor then? Does that help you to find the series current that is flowing around the whole circuit?

 

[blackout77]

Holy! You are brilliant. I test it and it works! I will keep this in my note. Thank you Berkeman!