Please check my work here:

Resistors of 30 ohms and 60 ohms are connected in parallel and joined in series to a 10 ohm resistor.
The circuit voltage is 180 volts.

Find:
a)the voltage of the parallel circuit

b)the voltage across the parallel circuit

c)the current through the 10 ohm resistor

Ans: So for voltage of parallel circuit I took 180V/30 ohms = 6A. I multiplied that by 20 ohms that I had found by 1/r total = 1/30 + 1/60 = 20 ohms. So I got 120 V for voltage of the parallel circuit.

For voltage across the parallel circuit, I originally found 180V because I included the 60 V from the series. From what the tutors have said, this is the same problem as above one. Therefore, should my answer be 120 V instead of the 180V?

c) I used I = V/R = 60 V / 10 ohsm = 6 amps for the current through the 10 ohm resistor.

So I found: 120 V, 120 V again???, and 6A. Have I finally got it?

Nuts to your logic.

voltage in the parallel branch is due to the effective resistance of the parallel branch x total current.

effective resistance of parallel branch:
20 ohms, your work is correct there.
Total resistance: that 20 ohms in series with another 10, total 30 ohms.
total current: 180/30=6amps (note this is not what you did).
voltage on parallel branch: 20ohms*6amps 120 volts
current through 10 ohm: 6 amps.

Now your questions: what does a) mean? It makes no sense.

To check your work, let's go through each question one by one:

a) To find the voltage of the parallel circuit, you correctly used the formula I = V/R, where I is the current, V is the voltage, and R is the resistance. However, the current you calculated, 6A, is incorrect.
The total resistance in a parallel circuit is found using the formula 1/Rtotal = 1/R1 + 1/R2 + 1/R3 + ... In this case, R1 = 30 ohms and R2 = 60 ohms.
So, the total resistance is 1/Rtotal = 1/30 + 1/60 = 1/20.
Taking the reciprocal, Rtotal = 20 ohms.

The formula for calculating the voltage of a parallel circuit is V = I * R. Substituting the values, V = 6A * 20 ohms = 120V.

Therefore, your answer for the voltage of the parallel circuit should be 120V, not 180V.

b) The voltage across the parallel circuit is the same as the voltage of the parallel circuit. So, the correct answer is also 120V.

c) To find the current through the 10 ohm resistor, you correctly used the formula I = V/R. Substituting the values, I = 120V / 10 ohms = 12A, not 6A.

Therefore, your answer for the current through the 10 ohm resistor should be 12A, not 6A.

In summary, the correct answers are:
a) The voltage of the parallel circuit is 120V.
b) The voltage across the parallel circuit is also 120V.
c) The current through the 10 ohm resistor is 12A.

I hope this helps! Let me know if you have any further questions.