Respuesta :

amna04352

Answer:

150

Step-by-step explanation:

Volume = ½(1.4+0.6)×2×1

= 2 m³

Rate of decrease: 2 × 1 × (20/100)

= 0.4 m³ in 30 mins

= 1/75 m³ per minute

1/75 = 2/t

t = 150 minutes