What is the equivalent resistance of a circuit that contains four 75.0 resistors connected in series to a 100.0 V battery?

The total resistance of the circuit is found by simply adding up the resistance values of the individual resistors. It is simply:

R = R1 + R2 + R3 + ...

Therefore, the equivalent resistance of a circuit that contains four 75.0 resistors connected in series would be R = 4x75 = 300 ohms.

Hope this answers the question.