If the mixing ratio of a parcel of air is 6 grams per kilogram and the relative humidity is 25 percent, the saturation mixing ratio is grams per kilogram.

-

24 grams per kilogram.

Explanation: -

We know that

The mixing ratio = actual (measured) mass of water vapor (in parcel) in grams / mass of dry (non water vapor) air (in parcel) in kilogram

The saturation mixing ratio = mass of water vapor required for saturation (in parcel) in grams/ mass of dry (non water vapor) air (in parcel) in kilograms

Relative humidity = actual (measured) water vapor content/ maximum possible water vapor amount (saturation)

Thus saturation mixing ratio = Mixing ratio / relative humidity

= 6 / (25/100)

= 24