....................

15. 10 x 15 = 150
18. 1/2 abad = 50 th . 50 + 6 = 56
19. 2 gros = 144 x 2 = 288
20 lusin = 12x20= 240
288-240=48
17. 7,5 kw =750kg
1,2ton = 12 kg
750 + 12 +675=1.437
1,5 ton = 15 kg , 1.437-15 =1.422