Example $9\mathrm{.}1-3($choosing a Telephone company$)$

subject to

Minimize $z=\mathrm{.}25x_1+\mathrm{.}21x_2+\mathrm{.}22x_3+16y_1+25y_2+18y_3$

$x_1+x_2+x_3=200$

$x_1,200y_1$

$x_2,200y_2$

$x_{3}200y_3$

$x_1,x_2,x_{3}0$

$y_1,y_2,y_3=(0,1)$

The optimum solution yielos $x3=200,y3=1$

find the optimal solution using big M method

z equal $62($supposed to be$)$