How many noughts are at the end of these giant numbers?
Lyndon chose this as one of his favourite problems. It is
accessible but needs some careful analysis of what is included and
what is not. A systematic approach is really helpful.
Weekly Problem 17 - 2010
The value of the factorial $n!$ is written in a different way. Can you work what $n$ must be?
How many zeros are there at the end of the number which is the
product of first hundred positive integers?