Statement$-2:$ Intensity of waves of given frequency in same medium is proportional to square of amplitude only.
${y_1} = 0.05\,\cos \,\left( {0.50\,\pi x - 100\,\pi t} \right)$
${y_2} = 0.05\,\cos \,\left( {0.46\,\pi x - 92\,\pi t} \right)$
then velocity is..... $m/s$