tolong yaa no. 6 aja

6. Volume aquarium
= p × l × t
= 60 × 30 × 50
= 90000 cm^3

Volume air
= 90000 × 2/3
= 60000 cm^3

Vol. aquarium - Vol. Air = Vol. balok
90000 - 60000 = p × l × t
30000 = (p × l) × 100 cm
30000 / 100 = p × l
300 cm^2 = p × l

P × l = luas alas balok, jadi luas alas balok = 300 cm^2