Answer:
150 ohm
Step-by-step explanation:
So, we have 3 resistors: 25, 50 and 75 ohm in series.
also remember that the ohm's law: V=IR
then:
V(tot) = V1 + V2 + V3 (in our case)
I R (tot) = I R1 + I R2 + I R3
we cancel these currents I ; because its constant in the circuit.
R(tot) = R1 + R2 + R3
R(tot) = 25 + 50 + 75 = 150 ohm (final answer).