How to divide the inheritance

Question

Khwarizmi stipulated that if his wife had a son he would inherite  2/3 of his estate and his wife the remaining 1/3 . If she were to have a daughter she would inherite 1/3 and his wife the 2/3 of his estate. The wife had twins a boy and a girl. How should the inheritance have been divided among his wife son and daughter in order to respect khwarizmis wishes? 

Answer 1

1/5 goes to each party