The charge on capacitor of capacitance $$15\mu$$F in the figure given below is

Given:
Capacitors in series: 10 μF,  15 μF,  20 μF
Potential difference V=13 V

Step 1: Equivalent Capacitance (Series)

$$\ \frac{\ 1}{C_{eq}}\ =\ \frac{\ 1}{10}\ +\ \ \frac{1\ }{15}\ +\ \ \frac{1\ }{20}\ =\ \ \frac{\ 6\ +\ 4\ +\ 3}{60}$$
$$C_{eq}\ =\ \ \frac{\ 60}{13}μF$$

Step 2: Charge in Series Combination

$$Q=Ceq​⋅V=\ \frac{\ 60}{13}\times\ 13=60μC$$

Step 3: Charge on Each Capacitor
In series, charge is same on all capacitors.

Final Answer:

Q=60 μC