A Small Puzzle For All You Brilliant People - XLS Download

Hello friends.
An attachment with small puzzle.
All the best.
Regards,
Zooni

First send 1 and 3, bring 1 back
then send 8 and 12, bring 3 back
now send 1 and 6, bring 1 back
finally send 1 and 3
Regards
Saritha

hey Zooni,
i cracked the puzzle....find the answer:
on first chance 1&3 will go together then 1 will return back and on second chance 8& 12 will go together and 3 will return back then on third chance 1&6 will go together and 1 will return back and finally will together crossed the bridge.
Regards
Saroj/Rose