Trackers Inc. produces backpacks in two models, journey and trek. The journey model requires 4 hours of labor, and the company makes a profit of $40. The trek model requires 6 hours of labor, and the company
makes a profit of $80. The distributor will accept no more than 4 trek models and 15 journey models per week.
What is the minimum number of hours of labor that are required for the company to make a profit of at least
$400 per week?
a