5.W. MAKING THREE PIECES OF TOAST
This involves an old fashioned toaster which does one side of two pieces at a time. An alternative version is frying steaks or hamburgers on a grill which holds two objects, assuming each side has to be cooked the same length of time. The problem is probably older than these examples.
Sullivan. Unusual. 1943. Prob. 7: For the busy housewife.
J. E. Littlewood. A Mathematician's Miscellany. Op. cit. in 5.C. 1953. P. 4 (26). Mentions problem and solution.
Simon Dresner. Science World Book of Brain Teasers. 1962. Op. cit. in 5.B.1. Prob. 40: Minute toast, pp. 18 & 93.
D. St. P. Barnard. 50 Daily Telegraph Brain Twisters. 1985. Op. cit. in 4.A.4. Prob. 5: Well done, pp. 16, 80, 103 104. Grilling three steaks on a grill which only holds two. He complicates the problem in two ways: a) each side takes a minute to season before cooking; b) the steaks want to be cooked 4, 3, 2 minutes per side.
Edward Sitarski. When do we eat? CM 27:2 (Mar 2001) 133-135. Hamburgers which require time T per side. After showing that three hamburgers take 3T, he asks how long it will take to cook H hamburgers. Easily shows that it can be done in HT, except for H = 1, which takes 2T. Then remarks that this is an easy version of a scheduling problem -- in reality, the hamburgers would have different numbers of sides, there would be several grills and each hamburger would have different parts requiring different grills, but in a particular order!
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