32 miles. I knew that 3 hours I went 8 miles. Then if I went 6 miles that means I went 16 miles. Then if I went 9 hours then I would have gone 14 miles. If I went 12 hours I would have gone 32 miles. I added three (3) to every hour until I got to 12, and I add eight (8) to every mile.
Length of train : 100 length of bridge : 400 distance covered by the train to cross the bridge : (100 + 400) = 500 time taken by the train to cross : 30
speed = distance / time speed = 500/30 speed = 16.67 meters per second <===
