A classroom of 12m x 25m x 4m requires 3 air changes per hour. At an air velocity of 2 m/s, the necessary duct cross section (in m2 ) is

A classroom of 12m x 25m x 4m requires 3 air changes per hour. At an a

1.	A classroom of 12m x 25m x 4m requires 3 air changes per hour. At an air velocity of 2 m/s, the necessary duct cross section (in m2 ) is
A.	0.50
B.	0.75
C.	1.00
D.	1.25
Answer» B. 0.75