Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

In order to complete the racing competition, the Mexico racetrack has to submit its top and the most famous three horses to win the competition. Due to an electrical storm, all the records are cleared and no one knows which horse holds the record. They all look identical and it becomes even more difficult to differentiate the horses. There are 25 horses in the Mexico racetrack. But there can be only five horses at a time on the track. What will the least number of races that can be conducted to find out the three fastest horses?

When is the top of a mountain similar to a savings account?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

What does below pictogram mean?

Here is a mathematical expression that also secretly tells a movie name. What movie is that?

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?

What is the difference between a jeweller and a jailer?

John: "Hi Teacher, What is your favourite movie ?".
Chemistry Teacher: "Indium Cerium Platinum Iodine Oxygen Nitrogen".
Ten seconds later... John replied I got it.

Do you?

The more of this there is, the less you see. What is it?