If it took _new_ potatoes thirty minutes to cook, how long did it take old ones?
In vain she searched for the answer.

There were plenty of potatoes.

They were mashed, whipped, scalloped, creamed, fried, and broiled; they were made into puffs, croquettes, potato border, and potato snow.

For many of these they were boiled first--"until tender," one rule said.
"But that doesn't tell me how long it takes to get 'em tender," fumed Billy, despairingly.

"I suppose they think anybody ought to know that--but I don't!" Suddenly her eyes fell once more on the instructions for boiling turnips, and her face cleared.