For a three-digit number, the number in the hundreds place is exactly 5 times the number in the ones place, and the sum of the numbers in the ones place, tens place and hundreds place is 9. What is the three-digit number?
一个三位数，百位上的数正好是个位上的数的5倍，个位、十位和百位上的数之和是9，这个三位数是多少．
<result>531</result>