Cara dan jawaban 12gros-72buah =…lusin

1 gros = 12 lusin
Artinya, 12 gros = 12 × 12 = 144 lusin

1 lusin = 12 buah
72 buah = 12 x
x = 6 lusin

12 gros – 72 buah = 144 – 6
= 138 lusin