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

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

Buy me, smell me or deliver me, I do not change.

Who am I?

What brings you down but never up?

Why do Chinese men eat more rice than Japanese men do ?

In a science lab, a petri dish hosts a healthy colony of yeast for an experiment. Now every minute, all the yeast cells divide into two. At noon, there was just a single cell of yeast and at 1:22, the Petri dish was half full. Can you calculate when the dish will be full of yeast?

Find The Missing Number In the Sequence.
6 25 64 ? 32 1

How is the moon similar to a dollar?

Which word does the below Plexor means ?