It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Keyboard words are not in alphabetical order, Why?

I am an eight letter word and I am a computer terminology.
The second, third and fourth letters make an animal.
The fourth, fifth, sixth, seventh and eighth letters make a weapon.
The first, second, third and fourth letters can be taken as an outcome of any exam.
The fifth, sixth, seventh and eighth letter combine to form a high end typing software.

Can you tell who am I ?

I taste better than I can smell. Who am I?

A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

Here is a mathematical expression that also secretly tells a movie name. What movie is that?

A horse was tied to a rope 5 meters long and the horses food was 15 meters away from the horse. How did the horse reach the food?

When you stop to look, you can always see me. But if you try to touch me, you can never feel me. Although you walk towards me, I remain the same distance from you. What am I?