Can you find out which number multiplied by itself will give the output as 12345678987654321?

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?

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

A man is walking down a road with a basket of eggs. As he
is walking he meets someone who buys one-half of his eggs
plus one-half of an egg.
He walks a little further and meets another person who buys
one-half of his eggs plus one-half of an egg.
After proceeding further he meets another person who buys
one-half of his eggs plus one half an egg. At this point, he
has sold all of his eggs, and he never broke an egg.
How many eggs did the man have to start with?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

How can I get the answer 24 by only using the numbers 8,8,3,3?

You can use the main signs add, subtract multiply and divide.

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?