Different lights make me strange by changing me into different sizes. What am I?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

If two's company, and three's a crowd, then whats four and five ?

If,
9 * 8 * 7 = 65
8 * 7 * 6 = 50
7 * 6 * 5 = 37

Find
6 * 5 * 4 = ?

John was working on a Chemical Mixture whose weight comprise 90% liquid and 10% solid. The total weight of the mixture is 20 pounds. After a while, John noticed that some of the liquid evaporated and now the liquid comprises just 50% of the weight.

What is the weight of the chemical mixture now?

You have two buckets - one holds exactly 5 gallons and the other 3 gallons. How can you measure 4 gallons of water into the 5 gallon bucket?

(Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)

Most people think of me as money. But when they find me in the water, they won’t get any money out of me. What am I?

Below rebus represent famous DiCaprio movie. Can you name it?

You have a square. What you have to do is cut and reassemble the square such that you create a Red Cross sign that has the same volume as that of the square.

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