please solve it properly.

Q.6: A 100kg batch of granular solids containing 30% moisture is to be dried in a tray drier to 15.5% by passing a current of air at 350K tangentially across its surface at a velocity of 1.8m/s. If the constant rate of drying under these conditions is 0.0007kg/sm2 and the critical moisture content is 15%, calculate the approximate drying time. Assume the drying surface to be 0.03m2/kg dry mass