Abstract
We consider the comic task of obtaining the number 100 from a six-digit bus ticket number by placing parentheses and symbols for arithmetic operations between some digits. The solution algorithm for a fixed number is reduced to enumerating all binary trees having exactly six terminal nodes with the signs of operations in internal nodes. For six-digit numbers that do not contain duplicate digits and the digit 0, the problem has a solution for all numbers except the only number 746189. It is impossible to obtain a hundred from this strange number 746189.
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Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 23, No. 3, pp. 37–47, 2020.
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Borisenko, V.V., Rakhmatov, R. A Hundred from a Bus Ticket. J Math Sci 269, 290–297 (2023). https://doi.org/10.1007/s10958-023-06281-9
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DOI: https://doi.org/10.1007/s10958-023-06281-9