impedance Questions

An inductor of inductance $L$, a capacitor of capacitance $C$ and a resistor of resistance $R$ are connected in series to an ac source of potential difference $V$ volts. Potential difference across $L,C$ and $R$ is $40\text{V},10\text{V}$ and $40\text{V}$, respectively. The amplitude of current flowing through LCR series circuit is $10\sqrt{2}$. The impedance of the circuit is: