Using momentum conservation m_{1} \ imes 2 - 4m_{2} = (m_{1} + m_{2}) \\Rightarrow m_{1} = 5m_{2} Ratio of K.E =\\dfrac{\\dfrac{1}{2}\ imes m_{1} \ imes(2)^{2}}{\\dfrac{1}{2}\ imes m_{2} \ imes(4)^{2}} =\\dfrac{5m_{2}\ imes 4}{m_{2}\ imes 16} = 1.25