A rich man named Richard Ellis had been counting his money 的

A rich man named Richard Ellis had been counting his money。 When he finished,he carelessly 1eft a $ 100 bill on his desk。 But when he returned for it a short while later,it was gone。 Only two persons could have seen the bill。0ne was the maid; the other was the butler。 The maid told him that she thought it was not a safe on the desk and had placed it under a green book。 But when they looked,the bill was not there。 The butler said he had found the bill where the maid had left it。 He had put it inside the book。 Where he thought there was less chance that somebody would find it。 He had written down the numbers so that he would not forget them。 The bill was between pages 35 and 36,he said。 But when they looked there was no money in the book。 After hearing their stories ,he called the police。 It was clear/certain to him that who had taken the money。