Call me delusional, but I can't shake the weird hunch that there's supposed to be a drawing to go along with this question, showing the values of the resistors and exactly how they're connected to the battery.
In a series circuit, the voltage divides across the resistors in proportion to their resistances. If two resistors in series are the only things connected to your battery, then the voltage across each resistor is . . .
(12 volts) x (the resistance of that one resistor) / (the sum of both resistors) .
