Please help me, I really need your physics help?

Question

I worked out the density of dry air by using the pressure of 994 hectapascals and the temperature of 30 degrees celcius to get the following
Rho=994×100 / (287.0×303.13) = 1.1426 kg/cubic metre.

Now I need to work out the mass of a pocket of air with the above conditions using the volume of 90×106 m3. You don't have to calculate it, just show me the equation I would use. Please, you're my only hope.

Answer 1

Mass = density x volume

density = 1.1426 kg/m^3 (your calculation)
volume = 90*10^6 m^3

just multiply

Answer 2

u say one cubic meter has a mass of 1.1426kg, right?
what would the mass of TWO cubic meters be?
well, that would be 2 times 1.1426kg
How about THREE cubic meters? that would be 3 x1.1426kg
How about 9x10 to the seventh meters?
well that would be 9x 10 to the seventh times 1.1426kg.
Sometimes it helps to "think" it out, instead of just being a slave to D=MxV

Answer 3

m = ρV = (1.1426 kg/m^3)(90*10^6 m^3)