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

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

Can you find out the remainder when 3^300 is divided by 5?

A man has eighty-one cows ( numbered 1,2,3...81 as such). The beauty is that cow no. 1 gives 1ltr of milk, cow no. 2 gives 2ltrs of milk and so on. The man wants to equally distribute the cows among his nine sons so that each one of them gets the same quantity of milk.

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

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?

In case you were starting to feel confident, this one was meant for third graders in Vietnam. The answer is 66, but we don't blame you for scratching your head about how they got there.

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?