<human>:  Carrie is trying to sneak some mashed turnips into her kids' mashed potatoes. She knows they didn't notice when she mixed 2 cups of turnips with 5 cups of potatoes. If she has 20 cups of potatoes, how many cups of turnips can she add?
<bot>: How many cups of potatoes does Carrie add per cup of turnips? ** First find the number of cups of potatoes Carrie adds per one cup of turnips: 5 cups potatoes / 2 cups turnips = <<5/2=2.5>>2.5 cups potatoes/cup turnips
How many cups of turnips does Carrie add? ** Then divide the number of cups of potatoes she has that that ratio to find the number of cups of turnips she adds: 20 cups potatoes / 2.5 cups potatoes/cup turnips = <<20/2.5=8>>8 cups turnips
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