When there are 5 molecules of fructose on each side of the membrane.
Explanation:
The solution will reach equilibrium fro fructose when there are 5 molecules of fructose on each side of the membrane.
A membranous system is said to be at equilibrium when there are equal concentration of a particular molecule on both sides of the membrane.
<em>Hence, for a membranous system with 10 molecules of fructose on one side, an equilibrium can only be reached for fructose when there are 5 molecules on one side and the remaining 5 molecules on the other side. </em>
