The sum of the ages of A, B, and C is 64 years, the sum of the ages of B, C, and D is 36 years, and the sum of the ages of A and D is 2 times the sum of the ages of B and C. times, what is the sum of the ages of the four of them?
甲、乙、丙三人的年龄之和是64岁，乙、丙、丁三人的年龄之和是36岁，甲、丁二人的年龄之和是乙、丙二人年龄之和的2倍，他们四个人的年龄之和是多少岁？
<result>75</result>