18 Sep AUGUST PUZZLER!
Below is the solution to the August Puzzler. While the answer “1 second. Ants are evil creatures and that’s the amount of time it takes to torch the stick and kill them all” is a completely logical answer, the correct answer is 12!
Here’s how we got there.
Solution: The key insight to this problem is to realize that two ants colliding and turning around instantly is the EXACT SAME as the two ants walking through each other! We can think of it this way because all the ants are indistinguishable (they are not labeled, and each has the same speed). Once we have re-framed the problem this way, we can see that the MAXIMUM amount of time for all the ants to fall off the stick is the same amount of time it would take one ant to walk all the way across the stick!
ANTS ON A STICK!
25 ants are crawling along one side of a foot-long stick. Each of the ants crawls at a speed of 1 inch / second. If two ants meet head on, they both turn around and immediately continue crawling. If an ant reaches either end of the stick, it will fall off. What is the longest possible time (in seconds) before ALL ants fall off the stick?
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