A decimal, if its fractional part is enlarged by 3 times, the original number becomes 3.2; if its integer part is enlarged by 5 times, the original number becomes 10.4. Find this number.
一个小数，如果把它的小数部分扩大3倍，原数就变成3.2；如果把它的整数部分扩大5倍，原数就变成10.4．求这个数．
<result>2.4</result>