A carpenter makes chairs ($x$) and tables ($y$). A chair takes 2 hours and a table 3 hours, and he has 12 hours a day. Which constraint describes his time?

Explanation

1. 01

   Write each resource as (amount used per unit) × (number of units), added over the products.

2. 02

   'At most' or 'available' gives ≤, 'at least' or 'must give' gives ≥; a profit is maximised and a cost minimised.