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

Which letter of the alphabet has the most water?

If I put in one canary per cage, I have one bird too many. If I put in two canaries per cage, I have one cage too many. How many cages and canaries do I have?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

Ten coins have been arranged as you can see in the given picture. In this arrangement, a triangle is formed pointing upwards. You have to invert the position of the triangle and make it point downwards while changing the position of 3 coins only. Can you do it?

What is common among 11, 69, and 88?

What are the five permanent members of the UN Security Council?

a) France, Germany, Italy, Japan, United Kingdom
b) Canada, Mexico, Saudi Arabia, Turkey, United Arab Emirates
c) Brazil, India, Nigeria, South Africa, South Korea
d) China, France, Russia, United Kingdom, United States

Solve the equation in the image by looking at the pattern closely.

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

What do you get if you add 2 to 100 four times?