please help me number 20

Diketahui 1 menit = 1/2 liter
Ditanya 1 1/3 jam =
Jawab :
1 Jam = 60menit
1/3 jam = 1/3 x 60 = 20 menit

= 60menit + 20menit x 1/2liter
= 80 x 1/2
= 40 liter