Answer
Venting Mass flow rate = 0.036 kg/sec
Vented mass in a day = 3110.4 kg
Work Step by Step
1#
Venting Mass flow rate = Density*Volume flow rate
Venting Mass flow rate= $1.2 kg/m^{3} \times 30 \times 10^{-3} m^{3}/sec$
Venting Mass flow rate= 0.036 kg/sec
#2
Vented mass in a day = $0.036 kg/sec \times 24 \times 3600 sec$
Vented mass in a day= 3110.4 kg