no 19, 20, 21 ya kak sama caranya ak gk ngerti terima kasih

19 jarak=kecepatan ×waktu

w =50 menit=0.8 jam
k = 60 km/jam
j = 60 × 0.8
j= 48=50 jawaban B

20.=2 dm kubik = 2×1000= 2000 cm kubik
=2000÷4
=500 .jawaban A
21.jawaban A kalo gak saalh