(December 23, 2018 at 4:00 am)Javaman Wrote:(December 1, 2018 at 2:54 pm)T0 Th3 M4X Wrote: There's an alternate way to solve the original problem.
You can weigh them 3vs3. If the heavier ball is in one of those two groups in will tip the scale to that side, then you work from that group of 3. If it's not, you know it's one of the remaining 2 balls. So you can actually get it in two if it happens to be in the set of two, but no more than 3 if it isn't.
Actually, you are guaranteed to get it in two steps if you start by weighing them 3x3.
If one of the sets of three is heavier, all you need to do is pick any two balls from the heavier trio and weigh them against each other. If the scale tips for one, you obviously have identified the heavier ball. If the scale remains perfectly balanced, then the ball you didn't weigh must be the heavier one.
So, two steps.
Well played sir.
