bagaimana cara ngerjain no. 18 & 19 ?

18. Waktu = 08.45 - 06.30 = 2 jam 15 menit --> 2 15/60jam
= 2 1/4 jam
= 9/4 jam

Jarak = 90 km

Kec = jarak / waktu
= 90 / (9/4)
= 90 x 4/9
= 40 km/jam

19.debit = Volum / waktu
= 2 m^3 / 15 menit
= 2 m^3 / (15/60) jam --> 1/4 jam
= 2 m^3 x 4/1
= 8 m^3/jam

Nomer 19. D = v ÷ w
= 2/15 × 60
= 4 m3/jam (B)