What goes up but never comes down?

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

The doctor prescribed you to take one pill from the bottle every half an hour. The bottle is now left with only three pills.

How long do you think you have before you run out of pills?

John was working on a Chemical Mixture whose weight comprise 90% liquid and 10% solid. The total weight of the mixture is 20 pounds. After a while, John noticed that some of the liquid evaporated and now the liquid comprises just 50% of the weight.

What is the weight of the chemical mixture now?

Two prisoners Jack and Jill are locked in a cell.
There is open window approx 40 feet above the ground of the cell.
They are never able to reach there.

Then they plan to escape by a tunnel and they start digging out.
After digging for more than 20 days, Jill comes with the different plan and they escaped.

what was the plan ?

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

What can jump higher than a building?

Whats the next number in the below number sequence pattern.

What is the word or phrase below?
R | E | A | D