People make me, save me, change me, raise me. What am I?

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

What does the below image rebus riddle means ?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?

You can see it everyday, But cannot touch it at will. What is it?

Can you count the number of triangles in the picture below?

I have Rs.50 and I spend it in the way as below.