A tuning fork of 512 Hz is used to produce resonance in a resonance tube experiment. The level of water at first resonance is 30.7 cm and at second resonance is 63.2 cm. The error in calculating velocity of sound is (JEE 2005)
a. 204.1cm/s
b. 110cm/s
c. 58cm/s
d. 280cm/s