A person measures the depth of a well by measuring the time interval between dropping a stone and receiving the sound of impact with the bottom of the well. The error in his measurement of time is $$\delta T=0.01$$ seconds and he measures the depth of the well to be $$L=20$$ meters. Take the acceleration due to gravity $$g = 10 ms^{-2}$$ and the velocity of sound is $$300 ms^{-1}$$. Then the fractional error in the measurement, $$\frac{\delta L}{L}$$, is closest to