How many sides does a circle have?

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?

It's a 7-letter word.
If we remove 1 letter from it, it remains the same.
If we remove 2 letters from it, it remains the same.
If we remove 3 letters from it, it remains the same.
If we remove all the letters from it, still it remains the same.
What is it?

I am green and found in the forest and have needles instead of leaves. What am I?
Hint 1: It can be used for Christmas decorations.
Hint 2: I have a strong, scent that is used in air fresheners.

In a town, there are over 100 flats.
Flat-1 is named first flat.
Flat-2 is named second flat.
Flat-3 is named third flat.

A visitors 'Victor' decides to walk through all the flats, he finds all the flats except flat-62.
Victor later founds that the local of the town have given it another name.

What is the name of the Flat?

A very interesting trivia question for all.

Why do men's shirts have their buttons on the right side and women's have buttons on the left-hand side?

Only one colour, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
What is it?

Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

What has to be broken before you can use it?