45. Four combines of brand "K" and three combines of brand "N" harvest as much in 5 days as three combines of brand "K" and five of brand "N" do in 4 days. Which brand of combine harvests more in a day?
45. Let a combine harvester of brand "K" harvest $x$ hectares in one day, and a combine harvester of brand "N" harvest $y$ hectares. Then we can write the equation $5(4 x+3 y)=4(3 x+5 y)$, from which $8 x=5 y$. From the last equation, it is clear that $y>x$. Answer. A combine harvester of brand "N" harvests more in a day than a combine harvester of brand "K".