С покупкой новых сортов семян расход на посев уменьшился с 52 т до 36 т . На сколько % уменьшился расход семян на посев ​. Мне нужно решение с объяснением

Stifling a huge yawn Petra (pull) herself up into a sitting position and (try) to free her mind from the clog of sleep. Slowly she (become) aware thft Sara (pull) her suitcase from under the bed and (fill) it by the simple method of taking out drawers of clothes and turning them upside down so that the contents (fall) into the case.