DEMAND$($TON$)$

$2.(20)$ A COMPUTER COMPANY MANES $10$ S ON EACH MODEL OF A AND $40$ S ON EACH MODEL OF B$.$ EACH COMPUTER REQUIRES THE FOLLOWING TIME ON PACKAGING AND PRODUCTION AS SHOWN BELOW.

A REQUIREMENT B REQUIREMENT TIME $60$

PRODUCTION

$2$

$4$

$60$

PACKAGING

$2$

$4$

$40$