What does this mathematical rebus means ?

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

I have one of the three numbers: 1, 2, or 3 in my mind. I speak only truth. You can ask me just one question for which I will only reply in yes or no or don't know. What question will you ask from me so that you are able to know the number?

Can you find the 09 errors in the picture below?

There is a barrel with no lid and some wine in it. 'This barrel of wine is more than half full,' said Curly. 'No it's not,' says Mo. 'It's less than half full.' Without any measuring implements and without removing any wine from the barrel, how can they easily determine who is correct?

Can you identify the Oscar-winning movie from the rebus below?

A sundial has the fewest moving parts of any timepiece. Which has the most?

I have teeth but i don't bite. Who Am I ?

what's the probability of getting a king or a queen from a pack of 52 cards?

You have 1023 apples and 10 bags. You have to distribute these apples in these 10 bags in any way you choose. But when I ask for a certain number of apples you have to give them in terms of bags without transferring the apples from other bags. How do you distribute the apples?