Problem:
Cagney can frost a cupcake every 20 seconds and Lacey can frost a cupcake every 30 seconds. Working together, how many cupcakes can they frost in 5 minutes?
Answer Choices:
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Solution:
Because 20 seconds is of a minute, Cagney can frost cupcakes in five minutes. Because 30 seconds is of a minute, Lacey can frost cupcakes in five minutes. Altogether they can frost cupcakes in five minutes.
The problems on this page are the property of the MAA's American Mathematics Competitions