What is black when you buy it, red when you use it, and gray when you throw it away?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?

A king sentenced a man to the death sentence for some crime he had committed. Known for his kindness, the king told the culprit that he had a choice to die in a way he decides.

The culprit was clever and said something that saved him from death. What method do you think he must have chosen for his death?

If you paint a brown house white it will become a white house. If the stoplight changes from red to green, then the light is green. So, if you throw a white shirt into the Red Sea, what will it become?

I am an odd number. Take away a letter and I become even. What number am I?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

There are three boxes of different sizes with three cupcakes inside each of the boxes in Christina's kitchen. At night her daughter wakes up and goes to the kitchen. She opens a box and eats all three cakes.

But in the morning Christina finds out that each box still had three cupcakes. How?

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

Replace the question mark with the correct number in below Picture: