Look at the add details for the question.?

Question

A 36.0- resistor and an 20.0- resistor are connected in series across a 15.0-V battery. What is the voltage across
(a) the 36.0- resistor and (b) the 20.0- resistor?

Answer 1

Sum the resistors to get total resistance in the circuit.
Use Ohm's Law to find the current that will flow (I = E/Rt).
Use Ohm's Law individually on the 36.0- resistor and the 20.0- resistor (E1 = I*R1, E2 = I*R2).

Answer 2

voltage divider
but we'll do it the other way
combine the two resistors and for Req
and then solve for the current
then you can apply ohms law to both resistors
the current is the same in both resistors