Respuesta :

amna04352

Answer:

150

Step-by-step explanation:

Rate at which volume decrease:

(1 × 2 × 20/100) ÷ 30

= 1/75 m³/min

Total volume:

½ × (1.4 + 0.6) × 2 × 1

= 2 m³

Time = 2 ÷ 1/75

= 150 mins