11. (6 points) The power company buried the same number of power poles on both sides of the road, totaling 402 poles, with a distance of 20 meters between each adjacent pair. Later, they were all replaced, and only 202 poles were buried. After the replacement, the distance between each adjacent pair of poles is $\qquad$ meters.
【Solution】Solution: $(402 \div 2-1) \times 20=4000$ (meters), $202 \div 2=101$ (poles),
$4000 \div(101-1)=40$ (meters);
Answer: The distance between each adjacent pair of poles after the modification is 40 meters.
Therefore, the answer is: 40.