1. a) V air yg keluar = 50 × 30 × (25 - 10) cm³

= 1500 × 15 cm³

= 22.500 cm³

b) V air yg tinggal = 50 × 30 × 10 cm³

= 15.000 cm³

c) tinggi air tempat baru = V air yg tinggal / L alas baru

= 15.000 / (100 × 25)

= 6 cm

2. s = ∛volume

s = ∛729

s = 9 cm

Luas permukaan = 6 s²

= 6 × 9 × 9 cm²

= 486 cm²

3. V = p × l × t

= (100 - 10 - 10) × (100 - 10 - 10) × 100 cm³

= 80 × 80 × 100 cm³

= 160.000 cm³

= 160 liter

lama = V / debit

= 160 liter / 5 liter/detik

= 32 menit

4. tinggi air = 2/3 × 30 cm

= 20 cm

kenaikan air = V kubus / L alas akuarium

= (12 × 12 × 12 cm³) / (50 × 30 cm²)

= 1728 cm³ / 1500 cm²

= 1,152 cm

5. V = L alas × t

= 80 dm² × 1 m

= 80 dm² × 10 dm

= 800 liter

banyak ember = 800 liter : 5 liter

= 160 buah