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 are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title

You find yourself in a strange place guarded by two guards.One of the guard always say truth while other always lies.You don't know the identity of the two.You can ask only one question to go out from there. What should you ask?

You along with your friend are standing in front of two houses. Each of those houses inhabits a family with two children.

Your friend tells you the below two facts:
1) On your left is a family that has a boy who likes accounts but the other child loves science.
2) On the right is a family with a seven-year-old boy and a newborn baby.

You ask him, "Does either of the family have a girl?"

To this, he replies, "I am not quite sure. But can you guess that? If you are right, I will give you $500."

Which family do you think is likely to have a girl?

Can you find out the number of the parking space in which the car is parked?

How many triangles can you find in this given picture?

A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?

Bobby and Wilbur decided to take their respective car out of the garage and race. None of them cheated and they both stood at the start time and decided to cover a distance in full throttle. The first to reach the mark was to be declared the winner.

Upon reaching the finishing mark, they found out that Bobby's car was 1.2 times faster than Wilbur's. Now, Wilbur had reached the mark about 1 minute and 30 seconds later than Bobby. Bobby's car reached the mark of 60 MPH on average.

Can you calculate the distance between the starting mark and the final mark with the help of the given data?

Through your logical capabilities, can you make 7 an even?

The teacher told the student that if he told a lie then he will be expelled from school and if he told the truth then he still is expelled from school.

What can a student say to prevent his being expelled from school?