I am an odd number. Take away a letter and I become even. What number am I?

Prove that twice of ten is the same as twice of eleven.

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

Using Only Five 5's and any mathematical operator make sum as 37

Can you find the thief by just looking at the picture below?

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

I got a bee but no honey.
got an eye but am still blind.
got a sea but no water.
got a tea but no coffee.
got a why but no answer.

What Am I?

I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?

What is the next number in this series?

4,12,84,3612....

When a clock is observed, the hour hand is at a minute mark and the minutes hand is six minutes ahead of it.

When the clock is observed again after some time, the hour hand is precisely on a different minute mark and the minute hand is seven minutes ahead of it.

Can you calculate how much time has elapsed between the two observations?