Answer:
Yes, because the bike order meets the restrictions of 4c + 6a ≤ 120 and 4c + 4a ≤ 100
Step-by-step explanation:
The constraint on build hours is ...
4c +6a ≤ 120
The constraint on test hours is ...
4c +4a ≤ 100
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The latter constraint requires the total number of bikes (c+a) be at most 25. The order under consideration is for 20 bikes, so easily meets this constraint.
The constraint on build hours has "c-" and "a-intercepts" of 30 and 20, respectively. That is, if all of the the bikes being built were adult bikes, at most 20 of them could be built.
The two constraints together tell you that <em>any order of 20 or fewer bikes</em> can be satisfied. The order in question is for 20 bikes, so can be built.