a double-digit number plus nine times of its ones is 100.what is sum of its figures on its digits.要结果

问题描述:

a double-digit number plus nine times of its ones is 100.what is sum of its figures on its digits.
要结果

1
一个两位数加上自身的九倍,结果为一百.那么他各位数相加是多少?
两位数是10嘛,于是答案是1.