back-of-an-envelope

English

Adjective

back-of-an-envelope (not comparable)

1. Alternative form of back-of-the-envelope
   • 2021 March 24, Christian Wolmar, “Railways must sell themselves and offer a better product”, in RAIL, number 927, page 46:

     Now, those Treasury mandarins unfamiliar with the railway might assume on the back of an envelope that if only 80% of trains are running, then that will cost 20% less. If only it were that simple.