(5)
Mathematically, the given problems now reduces to:
Maximise Z = 250x + 75y
subject to the constraints:
5x + y ≤ 100
x + y ≤ 60
x ≥ 0,  y ≥ 0
So, we have to maximise the linear function Z subject to certain conditions determined
by a set of linear inequalities with variables as non-negative There are also some other
problems where we have to minimise a linear function subject to certain conditions
determined by a set of linear inequalities with variables as non-negative Such problems
are called Linear Programming Problems Thus, a Linear Programming Problem is one that is concerned with finding the
optimal value (maximum or minimum value) of  a linear function (called objective
function) of several variables (say x and y), subject to the conditions that the variables
are non-negative and satisfy a set of linear inequalities (called linear constraints)