english: Dividing the batteries into  sets of 3, 3, and 2 is guaranteed to get a working result  in 7 tries or less, no matter what order  you test the piles in.
non_english: Door de batterijen te verdelen in sets van drie, drie en twee, heb je gegarandeerd  binnen zeven pogingen resultaat, ongeacht in welke volgorde  je de sets test.