A fit person walking briskly can walk a mile in 13 minutes. An estimated average walking speed for calculating... An average person can walk one mile on a flat, well-groomed surface in 17 to 20 minutes. A fit person walking briskly can walk a mile in 13 minutes. An estimated average walking speed for calculating...
Mum's the word is a popular English idiom. It is related to an expression used by William Shakespeare, in Henry VI, Part 2. Mum's the word means to keep silent or quiet. Mum is a Middle English word meaning silent. The word may be derived from the mummer who does pantomime and just acts without saying anything. Note the phonetically similar German word stumm (Old High German stum, Latin mutus) meaning silent, mute.
mumble. 1  to speak in a low indistinct manner, almost to an unintelligible extent; mutter. 2  to chew ineffectively, as from loss of teeth: to mumble on a crust. 3  to say or utter indistinctly, as with partly closed lips: He mumbled something about expenses. 4  to chew, or try to eat, with difficulty, as from loss of teeth.