We know that
$\because \mathrm{K}.\mathrm{E}.=\frac{{\mathrm{P}}^2}{2\mathrm{M}}$
    Where  P = momentum,    K.E. = Kinetic energy
  $\mathrm{K}.{\mathrm{E}}_{\mathrm{A}}=\frac{{\mathrm{P}}_{\mathrm{A}}^2}{2{\mathrm{M}}_{\mathrm{A}}}\text{ and }{\mathrm{KE}}_{\mathrm{B}}=\frac{{\mathrm{P}}_{\mathrm{B}}^2}{2{\mathrm{M}}_{\mathrm{B}}}$ 
    given :  KEA = KEB
$\frac{{\mathrm{P}}_{\mathrm{A}}^2}{2{\mathrm{M}}_{\mathrm{A}}}=\frac{{\mathrm{P}}_{\mathrm{B}}^2}{2{\mathrm{M}}_{\mathrm{B}}}$     
$\text{ or }\frac{{\mathrm{P}}_{\mathrm{A}}}{{\mathrm{P}}_{\mathrm{B}}}=\sqrt{\frac{{\mathrm{M}}_{\mathrm{A}}}{{\mathrm{M}}_{\mathrm{B}}}}\text{ or }\sqrt{{\mathrm{M}}_{\mathrm{A}}}:\sqrt{{\mathrm{M}}_{\mathrm{B}}}$