What goes up but never comes down?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.

Can you count the number of triangles in the given picture?

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?

Below is the sum of symbols in each row and column in the figure. Analyzing the figure, can you find out the value of the symbols?

The Judge knows that Alamgir was killed by his girlfriend Jasline, but the judge is unsure whether to punish her. Why?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

Can you identify the direction in which this bus is moving; left or right?

Hint: The bus is moving on the roads of London.

A bridge is about to collapse. There are four people P, Q, R and S on one of the sides. Before the bridge collapses, they want to cross it. Now since the bridge is too weak, it can only stand the weight of two people at a time. Also, it is night time and nothing is visible. They have just one torch with them.

Now P takes one minute to cross the bridge, Q takes two minutes to cross, R takes five minutes to cross and S takes ten minutes to cross.

The bridge will collapse in seventeen minutes. How will they be able to cross the bridge before it collapses?