Christine picked 10 pounds and Rachel picked twice as much, so Rachel picked 10*2 = <<10*2=20>>20 pounds of strawberries
Christine picked 10 pounds and Rachel picked 20 pounds for a combined total of 10+20 = <<10+20=30>>30 pounds of strawberries
They need 3 pounds of strawberries to make 1 pie and they have 30 pounds so they can make 30/3 = <<30/3=10>>10 strawberry pies
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