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 and solutions on this page are the property of the MAA's American Mathematics Competitions