D$-$Glucose and D$-$Fructose have the same chemical formula $(C_6{H}_{12}{O}_6)$ but different properties. Glucose is converted to fructose as shown in Figure $7,$ but $60\%$ is converted on one pass through the converter vessel so that unconverted material is recycled. Calculate the flow of the recycle stream per $kg$ of $100\%$ glucose fed to the converter. Ignore the solvent water used to carry the glucose and fructose.