Determine the voltage on the battery if the current in the circuit is 200 mA, and the resistors are connected mixed

Determine the voltage on the battery if the current in the circuit is 200 mA, and the resistors are connected mixed: R1 and R2 in series, R3 and R4 in parallel. R1 = 5 ohms, R2 = 7 ohms, R3 = R4 = 6 ohms.

Given:
R1 = 1 ohm.
R2 = 6 ohms.
R3 = 6 ohms.
R4 = 5 ohms.
R5 = 7 ohms.
Uab = 42 V.
Find: R – ?, I-?
Decision:
R = R1 + R2 + R3 + R4 + R5.
R = 1 + 6 + 6 + 5 + 7 = 25 ohms.
I = U / R.
I = 42/25 = 1.68 A.
Rtot = 1 * 6 * 6 * 5 * 7/1 + 6 + 6 + 5 + 7 = 50.4 Ohm.
I = U / R.
I = 42 / 50.4 = 0.83 A.