UGC NET CSE | October 2020 | Part 2 | Question: 4

Question

Consider the following linear programming (LP):

$\begin{array}{ll} \text{Max.} & z=2x_1+3x_2 \\ \text{Such that} & 2x_1+x_2 \leq 4 \\ & x_1 + 2x_2 \leq 5 \\ & x_1, x_2 \geq 0 \end{array}$

The optimum value of the LP is

• A. $23$
• B. $9.5$
• C. $13$
• D. $8$

Answer 1

ans is option 4)8  solution by graphical method    

 

Comments

we can also eliminate options here. By adding first 2 inequalities, we get, $3x_1 + 3x_2 \leq 9$.

It can also be written as: $x_1+z \leq 9$. So, $z \leq 9\; – \;x_1$

Since, $x_1 \geq 0$, So, $z\leq 9$. So, from given options, we can eliminate first 3 options.

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smart way to answer as per given options

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yes. Amazing trick.