The meaning of the question: You must have heard of the shortest/longest days of the year on the solstices. Well, basically the question means that in Kanyakumari, the maximum difference of time in the length of day and night is around 45 minutes i.e. if day is 11 hrs 55 min, night is 12 hrs 5 min (only 10 minutes difference). But in Kashmir its not like that. The night can be as short as 10.5 hrs and day 13.5 (around 3 hrs difference).
The meaning of the answer: This is because of the latitudes of the two places. As the Earth's axis is tilted, sunlight reaches different parts of the Earth differently. Kanyakumari lies near the equator, so it receives sunlight equally throughout the year. It is not so in Kashmir as it lies away from the equator.
Hope I helped. If I didn't, please inform me. I will do my best to clarify.