Alana chooses how many hours to spend studying for a test. If the final grade she can achieve per number of hours used for study is given by a concave production function, this implies that the _______ of each hour she uses to study _______ as the number of hours of study increase. / Alana kies hoeveel ure sy vir ‘n toets gaan studeer. Indien haar finale punt behaal per aantal ure wat sy studeer aangetoon word deur ‘n konkawe produksiefunksie, beteken dit dat die _______ van elke uur wat sy gebruik om te studeer _______ as die aantal ure wat sy studeer verhoog.