A flat sheet measuring 25 cm*25cm*1cm and weighing 1.2 kg was initially dried from both sides under constant drying rate conditions. The weight of the sheet was reduced to 1.05 kg in 1500 seconds. Another 50 cm*50 cm*1cm flat sheet of the same materials should be dried from only one side. Under the same constant drying conditions, the time required to dry from 16 kg to 14.3 kg (in seconds).