What's the only room from which no one can enter or leave

I add 5 to 9 and get 2. The answer is correct, so what am I?

Can you find the thief by just looking at the picture below?

A rain drop fell from one leaf to another leaf and lost 1/4th of its volume. It then fell to another leaf and lost 1/5th of the volume. It again fell on another leaf and lost 1/5th of the volume.



This process kept repeating till it fell on the last leaf losing 1/75th of its volume.



Can you calculate the total percentage of loss from the initial volume when the drop has fallen to the last leaf accurate up to two decimal places?

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?

Accidentally, two trains are running in the opposite direction and enter a tunnel that is 200 miles long. A supersonic bird that has fled the lab and taken shelter in the tunnel starts flying from one train towards the other at a speed of 1000 mph. As soon as it reaches the second train, he starts flying back to avoid collision and meets the first train again at the other end. The bird keeps flying to and fro till the trains collide with each other.

What is the total distance that the supersonic bird has traveled till the trains collided?

How many words can a pen with half refill write?

What does below Rebus mean ?

esgg sgeg gegs gsge

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

The below given figure comprises of a pattern through which you can determine the missing letter. Can you push your mind to find the pattern and add the missing letter?