There is a decimal whose integer part is 6, and the sum of the numbers in each digit of the decimal part is 15, and the numbers in each digit are different. What is the maximum number of this decimal.
有一个小数，它的整数部分是6，小数部分各个数位上的数字之和是15，而且各个数位上的数字都不同．这个小数最大是多少．
<result>6.96</result>