What is the average 25 meter 16 year old swim time in backstroke?

It would depend what event of 100 meters is being swum, if it is 100m freestyle, then I would say around a 1:00 to 1:10, same thing going for butterfly, and maybe only 5 or 10 seconds more for backstroke. For 100m breaststroke, a good time could be around 1:25 to 1:40, since breaststroke really varies between people, as well as being a slower stroke than other strokes. Lastly, if the event is the 100m IM (Individual Medley), a good time would be somewhere near the swimmer's "prime stroke" time (their best stroke that is not freestyle). This could be anywhere from 1:00 to 1:30, which is pretty fast for a meter race.