Answer: Density of methane is 0.92 g/L
Step-by-step explanation:
The relation between density and molar mass is :

where , d = density
P = pressure = 910 torr = 1.20 atm (760 torr=1atm)
M = molar mass = 16 g/mol ( for methane)
R = gas constant =

T = temperature = 255 K
Putting the values :

Thus density of methane is 0.92 g/L