For a second order kinetics, the reaction rate expression would be
-r = -dCa / dt = kCa^2 where k is the reaction constant and Ca is the concentration of reactant A.
Integrating this from Cao to Caf, will have the expression,
1/Caf - 1/Cao = kt
Substituting the given values and calculating for k,
1/0.00650 - 1/0.0100 = k(100)
k = 0.538 / M-s
