What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

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.

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

A man died, leaving $10,000,000 for his widow, 5 sons and 4 daughters. Each daughter received an equal amount, each son received twice as much as a daughter, and the widow received three times as much as a son.

How much did the widow receive?

Which of the following words don't belong in the group and why?
CORSET, COSTER, SECTOR, ESCORT, COURTS

What is the next number in this matchsticks series riddle?

How many times do a clock's hands overlap in a day ?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

What is harder to catch the faster you run?