posted by Jon .
You have a circuit with a 4 uF capacitor connected in series to 2 capacitors connected in parallel (2 uF and 1.5 uF). The battery is 12 V.
The first question asked what the circuit's equivalence capacitance was. I calculated it to be 1.9 uF, which is correct.
The next question asked how much charge flows through the battery as the capacitors are being charged.
I went q=cdeltaV=1.9 x 12= 23uC
which is incorrect. What is the correct answer and how do you get to it?
Well, the equivalent capacitance is found, so C=q/V or q= CV. You did it correctly, however, I would have carried it to more places, giving 22.4microC
I see nothing wrong with your approach.