1. The air temperature is 10°C and the air contains 2.87 grams of water vapor. What is the relative humidity?

Saturation mixing ratio of air parcel at 10 degrees is 7g/kg
2.87 / 7 x 100% = 41%

2. If the temperature of the air parcel in question 11 drops 10°C, how many grams of water vapor must condense out of the air?
can someone help me with this one?