Box A started out with 34 pebbles box B started out with 21 pebbles and box C started out with 20 pebbles
34 ;
Initially, box A had 34 pebbles. After transferring the pebbles between boxes A, B, and C, an equal number of pebbles ended up in each box. The calculations show that the initial numbers of pebbles were 34 in box A, 21 in box B, and 20 in box C.
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