I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

Christina is older than Kareena and Karishma. Katrina is older than Karishma and younger than Kareena. If Kareena has a brother named John, who is older than Christina, who's the youngest?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

It's a 7-letter word.
If we remove 1 letter from it, it remains the same.
If we remove 2 letters from it, it remains the same.
If we remove 3 letters from it, it remains the same.
If we remove all the letters from it, still it remains the same.
What is it?

Can you decipher the below rebus?

PBLUESAISNUERSES

Before Mount Everest was discovered, what was the highest mountain in the world?