Question

Screen-printing a batch of shirts requires 3 minutes per shirt in addition to 12 minutes of initial set-up time. If it takes 45 minutes to screen-print a batch of shirts,how many shirts are in the batch?

Answer 1

11 shirts

Explanation:

Since 12 of the 45 minute are devoted to setup, the actual printing time is 33 minutes. At 3 minutes per shirt, that's enough time for ...

(33 min)/(3 min/shirt) = 11 shirts

A batch consists of 11 shirts.

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Alternate solution

Another way to consider this is to realize that the setup time is the time required to print 4 shirts. 45 minutes would be enough time to print 45/3 = 15 shirts, but the time for 4 shirts is spent setting up. That leaves the batch size at 15 -4 = 11 shirts.