I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?

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?

I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and the cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.

How Long will it take to fill the bucket?

What does this mathematical rebus means ?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

What word begins and ends with an E, but has only one letter?

Which city is three-fifths chick two third cat and 50% goat?

How many letters are in the alphabet?

I am thinking of a five-digit number such that:
The first and last digits are the same, their submission is an even number and multiplication is an odd number and is equal to the fourth number. Subtract five from it and we obtain the second number. Then divide into exact halves and we get the 3rd number.

What number I am thinking of?