What is both possible and impossible at the same time?

Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

Take one out and scratch my head, I am now black but once was red. What am I?

Suppose we lay down two cups in front of you. One of the cups is filled with tea and the other one with coffee. Now we ask you to take a spoonful of tea and mix it with the coffee. At this moment, the coffee cup has a mixture of tea and coffee. You have to take that mixture (spoonful) and add it back to the tea.

Can you now tell if the cup of coffee has more tea or the cup of tea has more coffee?

81 x 9 = 801. What must you do to make the this equation true?

Count the Triangle in the figure given below:

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

The first person saw the bridge step on it and crossed,
the second person saw the bridge did not step on it but crossed,
the third person did not see the bridge did not step on it but crossed.
Who are these people?

What is red and smells like blue paint?

In a concert, Christina is performing a dance show with her group.
At 10:00, she and her crew were dancing in an absolutely straight line. At that time Christina was standing in 4th position from both the front and back end of the row.

What was the size of her crew?