what one word does the below rebus identifies?

Suppose that you are trapped on the surface of a frozen lake. The surface is so smooth and ideal that there is no friction at all. You cant make any grip on the ice and no wind is blowing to help you out. You have just a mobile phone with you which has got no reception disabling you to call for help.

How will you plan your escape before you freeze to death on the frozen lake?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

What's the only room from which no one can enter or leave

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

They are three errirs in this question. Can you find them?

How do you go from 98 to 720 using just one letter?

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?

What is the largest number you can write with just 3 digits?

A maths symbol is hidden in the below Bar Graph. Can you decipher it?