Relative Humidity

[essi088]

Hi,
Can somebody help me with this question please?

In humid air with a water content of 3 g / (kg dry air), liquid water is injected at a temperature of 30 ° C, after which the air temperature becomes 18 ° C and its relative humidity 50%. The total pressure is constant 1.013 bar and the mass of the dry air is 60 kg. Calculate:
a) the amount of water injected;
 b )the air temperature before water is injected

Edited November 14, 2019 by essi088