Tolong ya cuman 3 nomor

19) K = 400 m + 50 dm
= 400 my + 5 m
= 405 m
jarak = 405 m X 3
= 1215 (B)
20) 2 X 1 rim = 2 X 500 = 1000
1000 + 56 - 331 = 725 lembar (B)
21) 0,8 liter = 800 ml
320 CC = 320 ml
410 cm³ = 410 ml
800 - 320 - 410 = 70 ml (A)