# Is this linear programming problem right?

The problem is: Beth works a maximum of 20 hours/week programming computers and tutoring math. She receives 25 dollars/hour for programming and 20 dollars/hour for tutoring. She works between 3 and 8 hours/week programming, but always gives more time to tutoring. How many hours should she work at each job to maximize her income?

Let x = # hours programming and y = # hours tutoring.

My constraints are:

Total hours: x+y≤20
Hours programming: 3≤x≤8
Hours tutoring: y>x


My objective function is:

25x + 20y = maximum profit


Here is my graph:

And from looking at the corner points, I can say that the answer is 8 hours programming and 12 tutoring. Is this plus all my other work correct?

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@Someone just to make it clear, the reason is that when you say "$y>x$", you're saying "$y\ne x$". That's no good as we can see from the following ridiculous LPP: $\max z$ subject to $z<1$. As you can see, there is no solution. Why? Well $z$ can't be 1 cause $z<1$. But there is no next smallest number under 1, at least not in the real numbers. So strict inequalities make LPP's impossible to solve. –  crf Dec 9 '12 at 22:03