PROBLEM LINK:
Author: Full name
DIFFICULTY:
Very Easy
PROBLEM:
Find whether N circularly linked gears can rotate simultaneously.
QUICK EXPLANATION:
If N is odd the gears will be locked. If N is even they can rotate.
EXPLANATION:
Consider two linked gears A and B. If A rotates clockwise B rotates anti clockwise and vice versa. For N circularly linked gears, the Nth gear’s rotation has to be opposite to that of the first gear. This is possible if N is even.
AUTHOR’S SOLUTIONS:
Author’s solution can be found here.