A sine-wave generator with $20-\mathrm{V}$ peak output is applied across a series $R L C$ circuit. At the resonant frequency of $2.0 \mathrm{kHz}$, the peak current is $50 \mathrm{mA} ;$ at $1.0 \mathrm{kHz},$ it's $15 \mathrm{mA} .$ Find $R, L,$ and $C$