Andy is making fudge. First he needs to raise the temperature of the candy mixture from 60 degrees to 240 degrees. Then he needs to cool it down to 170 degrees. If the candy heats at 5 degrees/minute and cools at 7 degrees/minute, how long will it take for the candy to be done (in minutes)?
First find the total number of degrees the candy needs to heat up: 240 degrees - 60 degrees = <<240-60=180>>180 degrees
Then divide that amount by the rate the candy heats up: 180 degrees / 5 degrees/minute = <<180/5=36>>36 minutes
Then find the number of degrees the candy needs to cool down: 240 degrees - 170 degrees = <<240-170=70>>70 degrees
Then divide that by the rate the candy cool down: 70 degrees / 7 degrees/minute = <<70/7=10>>10 minutes
Then add the time for the candy to heat to the time for it to cool to find the total time: 10 minutes + 36 minutes = <<10+36=46>>46 minutes
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