Mehul 's activity
Algebra
Level
3
One day, Mehul wrote the integers 1, 2, 3, ... ,19, 20 on a blackboard. Then he erases any arbitrary numbers and replaces them with a new number of value . And he repeats it for another 18 times.
Show that there is only one number remain. What is the value of that number?
by
Nihar Mahajan