What is full of holes but still holds water?

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?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

There is something which you can be arrested for attempting but not for successfully completing.

1 + 9 + 8 = ?
considering, 28 + 8 + 92 = 10

Which is faster, Heat or Cold ? Explain.

Replace the question mark with the correct number.