13. (6 points) Xiao Ming and Xiao Jun set off from locations A and B respectively at the same time, heading towards each other. If both proceed at their original speeds, they will meet in 5 hours; if both increase their speeds by 2 kilometers/hour, they will meet in 3 hours. The distance between A and B is 30 kilometers.
【Answer】Solution: $3 \times 2 \times 2=12$ kilometers, the distance between A and B is $12 \div 2 \times 5=30$ (kilometers); Answer: The distance between A and B is 30 kilometers. Therefore, the answer is: 30.