nomor 41-47 pake cara

41. 1lusin=12 buah
12x3=36
36+3=39 (a)

41. 3 lusin + 3 = 3×12 +3 = 36+3 = 39(d)
42. ½ kodi = 10 (a)
43. ½ rim + 55 lembar = ½×500 +55 =305 (a)
44. 1 gros - 6 lusin -5 = 1×144 - 6×12 - 5
144 - 72 - 5 = 67 (a)
45.½ rim + 55 = ½×500 + 55 = 305 (a)
46. 5 lusin + 7 = 5×12 +7 = 67 (b)
47. 3 kodi + 2 lusin - 18 = 3×20 + 2×12 - 18
= 60+24-18 = 66 (c)

ket:
1 lusin = 12 buah
1 kodi = 20 buah
1 rim = 500 lembar
1 gros = 12 lusin = 144 buah