Problem
COM-B1-M06-P003 Stones in Piles
#3
★☆☆☆☆ Level 1 of 5
There are piles of \(3\), \(5\), and \(7\) stones. In one move, one stone may be moved from one pile to another. Can the piles become \(4\), \(6\), and \(10\)?
The total number of stones is preserved.
Initially there are \(15\) stones, while the target has \(20\). Since moving a stone does not change the total, the target is impossible.
Sum as invariant.