Moisture

A wet porous subtance in the open air loses its moisture at a rate proportional to the moisture content. If a sheet hung in the wind loses half its moisture during the first hour, then the time when it would have lost 99.9% of its moisture is (wether conditions remaining same)

A wet porous substance in the open air loses its moisture at a rate proportional to the moisture content. If a sheet hung in the wind loses half its moisture during the first hour, when will it have lost 95% moisture, weather conditions remaining the same?

A wet porous substance in the open air loses its moisture at a rate proportional to the moisture content. If a sheet hung in the wind loses half its moisture during the first hour, when will it have lost 90% , weather conditions remaining the same?

Consider the following statements: Assertion (A) The velocity of sound in air increases due to the presence of moisture in it. Reason (R ): The presence of moisture in air lowers the density of air. Of these statements-