11. (12 points) Fill in the blanks with numbers $1-5$, so that the numbers in each row and each column are not repeated, and each division operation from top to bottom or from left to right can be performed without a remainder. What is the three-digit number formed by the first three numbers in the second row?



The text above is the translation of the provided Chinese text, maintaining the original format and line breaks.
531
【Solution】Solution: First, based on the known number 5, the number below it cannot be even and can only be 3, so the number above 5 can only be 1.

Then, according to the number 3 in the third row, it can only be paired with 1, so the front is $4 \div 2$ and the back is 3 divided by 1.
Next, based on the pattern of the numbers in the first row, the final number can only be 3, i.e., $42 \div 3$.
Continuing the reasoning:
Therefore, the answer is: 531