It is known that 5x + 10Y is greater than or equal to 480, x y is an integer, and the minimum value of Z = 100x + 150y can be obtained, X y is a positive integer

It is known that 5x + 10Y is greater than or equal to 480, x y is an integer, and the minimum value of Z = 100x + 150y can be obtained, X y is a positive integer

Diagram, a formula can draw a coordinate graph. This problem can obviously be simplified later. It's very simple. 5x + 10Y greater than or equal to 480 can be reduced to x + 2Y greater than or equal to 96, and finding the minimum value of Z = 100x + 150y is 50 times of the minimum value of Z = 2x + 3Y. Right, a formula can draw a coordinate graph, and X + 2Y = 96 can draw a coordinate graph, and choose the greater part (how to determine is very easy, We can substitute it into the coordinate origin (see which side of the line the coordinate origin is on), make 2x + 3Y = 0 to get a straight line, and the intersection place in the graph is the corresponding x value and y value. We can bring in Z = 100x + 150y to calculate it

Let [x] be the largest integer less than or equal to x, for example, [4.25] = 4, [0.82] = 0, then the range of function y = [(x + 1) / 2] - [x / 2] (x ∈ n) is

{0,3/2}

25 / 3 minus (- 2 / 3) is equal to?

9