Consider the following linear program, which maximizes profit for two products: rMin z $=70$x$1+50$x$2$

subject to $40$x$1+30$x$2=>200($Constraint $1)$

$20$x$1+10$x$2=>70$ constraint $2$

x$1,$x$2=>0$

What is the upper limit of the second coefficient objective function?